08:47:44 Okay. For our next speaker, we will again be at an accelerator lab, but it'll be bringing the novel experiment and this, and the methodology of cold Adams and Adam interferometry to the laboratory. 08:47:59 And so it'll be Jason Hogan from Stanford, he's talking about matches and just 1000. 08:48:17 Great. Well, it's a pleasure to be here today. 08:48:21 My name is Jason Hogan and I tell you about amateur from a tree majors and if you change the title on you and I'll talk most of your majors 100 which is our installation that was just mentioned and majors 1000 is sort of a would be a next generation which 08:48:34 I'll mention on so a little bit but but I'll focus mostly on the hundred meters scale that we're doing a formula. 08:48:42 So, let me just 08:48:46 start by pointing out the sort of relationship to what I'm talking about today and some of the stuff we've heard about yesterday. 08:48:54 So, yesterday we heard some great talks about atomic clocks, and Adam interferometry is a closely related field. And, and, basically, the question I'd like to focus on today is, how can we leverage some of the these incredible gains in instability and 08:49:15 accuracy that we heard about yesterday so in the, in the field of atomic clock so we're talking about pushing into 19 digits of precision, for example. 08:49:28 And so there's a number of I think interesting fundamental physics experiments we can do with with with this technology. And in particular, I'll spend some time talking about gravitational wave detection and how it's possible to look for gravitational 08:49:42 waves and a new say let's say unexplored frequency range and complementary to existing detectors. 08:49:51 And, and then and then I'll also talk about sort of new, you could call them maybe hybrid sensors or Adam interferometer is that, take advantage of a lot of the the the sensitivity, or a lot of the techniques let's say that are that are common already 08:50:05 in the atomic clock community so So in particular, I've got sort of a picture here on the, on the left of the strontium clock transition used by optical lattice blocks. 08:50:21 This is a narrow transition with a long live excited state. You can take advantage of the same transition to build an atom interferometer and so just sort of as a pictorial description, down here we've got, you know, we heard about in clocks yesterday 08:50:32 also optical last clocks, this would be sort of the, what you might imagine, for that trapping a bunch of atoms and then standing wave potential. 08:50:41 And Adam interferometer is is is a closely related but instead of trapping the items we allow the atom to fall freely. And so you see the sort of parabolic trajectory is in the in the slower picture here showing the trajectory the atoms and we can we 08:50:54 can divide the atoms we function using pulses of light to split in have a travel on two distinct paths you see a lower path and upper path here, and the phase shift that this interferometer to essentially proportional to the area span by these two. 08:51:10 These two trajectories that phase shift can, in this case the sensitive to inertial forces that the atom experiences during this during the sequence so the acceleration in particular for this example. 08:51:22 And so you can use this to look for small forces and and and and other that can show up from new physics is also talking about. 08:51:31 I've got here on the right, some some sort of some quick pictures of. 08:51:36 Yeah, this idea of gravitational wave detection just to just to emphasize that you can imagine, building such a detector to look for gravitational waves using both atomic clocks, which is a picture from from such a paper here on using a lot of clocks 08:51:50 using to into satellites in orbit around the sun. 08:51:53 And then this is a picture from so my own work which is proposed similar proposal using Adam interferometry and I just want to emphasize that both of these approaches are are have a lot in common, and both look like an exciting viable approach to doing 08:52:08 this interesting science and there's different technical trade offs, but I think that the technologies are, as I said, have a lot in common. There's a lot we can certainly benefit from the atomic clock community in our, our editor from to work for example. 08:52:24 So a little bit about the science that I all focus on so there's there's a I guess I could describe a number of interesting federal physics tests I'm going to focus on three areas, mainly today. 08:52:38 And, and, for these it's really useful to have so called long baseline sensors so we're talking about. 08:52:47 Basically scaling up the kind of tabletop experiments that were used to think about it in ammo Tomich physics towards kilometer scale instruments. 08:52:59 And, and that's where this sort of majors. 08:53:11 Will comes along, in a few slides. So, so the three areas, I mentioned gravitational wave detection is plot here on the right showing the strain sensitivity of various gravitational wave detectors as a function of frequency. 08:53:13 And so this is a little bit small three but sort of over on the right here. There's the Lego sensitivity curve which is sort of above 10 hertz out to kill a hertz range where we've already seen really exciting science, sort of in the middle of the plot 08:53:28 here is our space space gravitational wave detectors, such as Lisa, which operating the mill hertz range up to sort of hundred megahertz. 08:53:36 But then between there's this sort of yellow band, which is called the mid band between a fraction of a hertz point three hertz to a few hurts were neither of those detectors is covering things very well and there's an opportunity to do some interesting 08:53:53 science, as I'll talk about so I guess the some of the sources that we've already seen, for example, that Lego has detected. 08:54:02 Black Hole binaries neutron star binaries those sources. 08:54:05 If all the time their frequency increases as they click get closer to final merger, and that implies that they they're emitting gravitational waves in this mid band as well. 08:54:14 And so you can see these sources at an earlier point in their evolutionary history when they're at lower frequencies. And that has some advantages. 08:54:23 In particular, in regarding multi master astronomy, which I'll say a bit about in the next slide. So that's gravitational waves. 08:54:30 Turns out the same style detector these long baseline Adam interferometer top type detectors can also look for ultra light wave like dark matter, which, which we heard a little bit about it yesterday. 08:54:41 And so these are typical models with with with with particles with mass on the order of 10 to the minus 14 ev sort of hurts level content frequencies. 08:54:53 And so that we can look for both scalar and vector couple of candidates and these can show up as as basically as time bearing clock shifts energy shifts so the atoms, or as new forces, as I mentioned, we can detect by looking in particular for things 08:55:10 forces that violate the equivalence principle and in a time dependent way in this case. 08:55:15 And then finally, and this is sort of more speculative. 08:55:18 The long baseline detectors gives us the opportunity to basically build very large adamant for so long drop times, allow us to split the atoms way function by larger distance. 08:55:30 This is a picture of sort of existing state of the art, where you see this is data showing rubidium interferometer where you see a sort of these multi little spikes are the probability distribution of the atom cloud at the moment of this image is taken, 08:55:43 and we're able to sleep unable to split, an atom's weight function by over half a meter using so called large momentum transfer Adam optics so advanced manipulations of the employee function allows us to make these macroscopic wave functions macroscopic 08:55:59 and distance, and the idea is by making these interferon there's large as possible, both in time and space you can look for, possibly violation, or you can test quantum mechanics and this regime, where we haven't explored before. 08:56:13 And so you can look for anomalies to coherence spontaneous localization theories, or other kinds of modifications of quantum mechanics that might prevent you from making such a macroscopic fraud. 08:56:27 So I mentioned multi messenger astronomy and I just wanted to say a word or two about that some one of the motivations why we think he's mid band graphics wave detectors are really exciting, sort of, independent of the approach that you the one uses to 08:56:41 make a detections is a really exciting range to do science. And so for this idea of sky localization How do you figure out where in the sky and event is sourced from. 08:56:52 And so if you have a gravitational waves, the way that Lego works to detect location is by looking at the delay of arrival at the two Legos so you can look at the light the excuse me the travel time of the gravitational wave between the two sensors on 08:57:06 opposite sides of the continent. 08:57:07 But the larger you can separate the detectors, the better terms of getting a lever arm for this differential arrival time to get a better sense of where the sources in the sky. 08:57:17 And so the advantage of the mid band. One of the advantages of this lower frequency sources is that the sources, they persist for a long time in the order of weeks to months. 08:57:27 And so in principle that allows you to make a detection even with a single detector, that's located on the earth. You can detect the gravitational wave for on the order of a year, so many months. 08:57:37 And so that gives you allow you to essentially synthesize a very large apertures you can basically look at the detector on these opposite sides of the sun, and get it, even though you have one detector your and you look at it in different differences 08:57:50 in time you can use that to effectively. Look for differential rival time and so that can give you a big enhancement the ability to find out where in the sky the detector is feeding with the sources, which would be really exciting, if you if you could 08:58:20 say. 08:58:20 So, a word about how these how that how that how the amateur from detector work it's actually very similar to how like it works for gravitational waves we imagine we have some straightaway propagating across space time and when it reaches the detector 08:58:35 the detector basically consists of a couple of inertial reference points in these black dots represent some test masses that are freely falling, and they're separated by some baseline else I'm distance and you look for a modulation and that link, and, 08:58:48 and in Lego that's done by looking at the at the light travel time between these tests masters which are these mirrors in one of the arms of Lego. And, in principle, that's enough to detect gravitational wave with the single baseline one of the arms of 08:59:03 Lego for example, Lego has two arms for technical reasons it needs, it's required to suppress the, the noise of the laser, so this is basically a common mode suppression techniques for laser noise and. 08:59:17 But in principle one set of taskmasters along the linear axis is enough to look for a modulation in the length and in fact the the atom interferometer approach that I'll outline is based on that idea is in a single baseline. 08:59:29 So, so, so this is a little more formalized what I was just describing the two ingredients you need then for this kind of gravity's way protectors you need some inertial reference points. 08:59:41 Some, in the case of Lego these are the enemies you need some object that's, that's basically freely falling unperturbed by non gravitational forces. 08:59:49 And, and then you need some way to measure the light travel time between those reference points so you need basically a good clock. 08:59:56 In the case of Lego that's provided by this auxiliary arm, there's compare the light travel time alone the two arms. But in principle here really good laser or, in this case, in the case of an admin from it or you could potentially use the atoms themselves. 09:00:11 themselves. And so, may just is the matter wave atomic cranium or informatics sensor it's based on the idea of basically combining these two ingredients into one so using the atoms, both as the really falling inertial test points, but also using the atoms 09:00:25 internal degree of freedom, as, as a clock in the way that we already do. In atomic timekeeping and use that as the face reference for measuring this light travel time. 09:00:35 And so in this sense that you can think of the atom is essentially an active proof mass, where the atomic coherence, it keeps a record of the lasers phase and and basically voids the need of having an auxiliary reference a baseline and so you can imagine 09:00:48 them doing single baseline gravitational wave detection, which has some, some advantages in particular for satellite missions. 09:00:59 So, so as I mentioned, there's a on the first slide, there's the idea here is to try to make this kind of hybrid sensor where we're taking advantage of these long live transitions use an atomic clocks but build to build an admin Frommer. 09:01:14 And so this is the idea of using the single photon transitions now in traditional Adam interferometry using alkali items, it's very common to use two photon transitions, like ramen transition to brag transitions, due to the lack of a long lift. 09:01:28 Excited optical transition, but in atoms that are used an awful lot of spots such as strontium. There are such long when state so we can imagine doing it wrong or with a single photon transition between this case these two levels here on this Saturday 09:01:42 where we can expect to have hundreds of 700 seconds of coherence in particular for that transition so you have plenty of time to do building that interferometer, and in these single photon transitions, have it at least in principle, a big advantage in 09:01:58 terms of the ability to cancel the noise of laser in the way that I described in previous slide, and using the sort of high IQ of this of this resonance the fact that we're able to have this call this coherence process, the entire duration of the experiment. 09:02:22 So you can see that a picture of the concept from ages on the right, this is actually a gradiometer so it's to Adam interferometer one, a two different heights let's say so this is one, maybe I'll show this picture first this, the got. 09:02:29 For example, a vacuum chamber and these two blue dots represent the two and there's no reference reference point so we want to use to to look for gravitational waves, let's say, and you can implement an atom interferometer and each of these two locations 09:02:42 simultaneously using the same laser pulses, and then space time diagram on the right shows such as have that works, you've got an admin from release to heights, and then the squiggly lines represent pulses of late, that are propagating along baseline 09:02:55 in the face difference between the Center for honors. 09:03:05 And that's the difference it turns out is encoded in the time that the atom spend in this excited state so so this the the different colors in this diagram represent the internal states so the blue, blue is the ground state red is the excited state. 09:03:18 And it turns out that the phase shift, just given here on the lower left is proportional to the energy splitting between the atomic level so that's what makes a here clock the clock. 09:03:29 The clock energy, and the late travel time back and forth across the baseline that's to oversee. 09:03:36 And so, If the baseline for example various due to a passing gravitational wave that's a change in L. Then you would see that delta l as a time during differential phase shift between these two adamant Frommer's. 09:03:51 And so, but as I mentioned this sort of is a two for one right so you can look for gravitational waves, but you're just a sensitive to variations in the clock energy omega a. 09:04:01 And one way that that can vary is due to coupling to an ultra light wave like dark matter field. And so, if there is such a field, then it would cause some energy shift, which we would also be able to see as a time during differential facial so you in 09:04:16 the same, the same machine you basically people up for both of these effects simultaneously. 09:04:23 So, so let me say a word or two about the state of the art, as I as I've said a few times, these are to really get into the interesting science range we need a long baseline What does that translate to kilometers Gail instruments so we need to look for 09:04:38 basically something similar in size to lie governor to hope to see gravitational waves, the current state of the art with Adam and from tree is sort of summarized here at a number of facilities around the world. 09:04:49 there are these 10 meter vertical drop terrorists. And so for example this one here at Stanford is a 10 meter vacuum chamber with Adam starts at the bottom and the atoms are launched in this, and fall for a couple seconds while we can do it admin from 09:05:03 a tree. There's also a number of other experiments around the world so in recent recent work in Hanover, Phil has a similar scale 10 meter device. There's a machine in China, and then recently in the UK is a on proposal, which has now been approved, I 09:05:19 should say, and is beginning to be designed which is another 10 meter scale machine with with ambitions towards making 100 meters in machines in the near future. 09:05:33 And so, and then I should also mention in my group at Stanford we're working on another 10 meter machine but this time using astronomy atoms the existing Stanford tower uses rubidium and and the strontium Adams, once again I'm motivated by the existence 09:05:49 of these clock transitions. And so we want to demonstrate that we can do the same sorts of experiments that have already been done with alkali Adams, using these clock transitions and so we built to astronomy madam sources, and we're now in the process 09:06:01 of building this 10 meter scale vacuum chamber where we'll have Adam services, one one sort of halfway up on what the bottom that will allow us to make the gradiometer that I described in the previous slide is this sort of a prototype for for the majors 09:06:15 experiments that that we're excited to do. 09:06:19 So there's actually a number of groups around the world that has started to extend from the current state of the art to too long baseline sensors. So this is kind of a selection of those. 09:06:32 And so as I mentioned that my work is on me just all say a word about that. 09:06:37 In on the next slide, but I want to make sure to emphasize all that this is that there's there's sort of an exciting time right now where, where as I said there's lots of groups that are starting to do this so that the people are excited about the science 09:06:49 opportunities here. So in France there's nega, which is the horizontal machine with, sort of, sort of, couple hundred meter long vacuum chamber with a number of Adam sources along the length him to do gravitational wave detection and similar science. 09:07:07 I just, I mentioned a on in the UK, which is is designed with, with an emphasis on on on being collaborative with majors and essentially acting as another detector where we can use will be so we can cross correlate data between these two devices on opposite 09:07:24 sides of or separate by large distance, which is great for things like gravitational wave science where you want to have confirmation detection is real. 09:07:33 And then, in China, there's the saga effort where they're building vertical and horizontal vacuum chambers in a mountain with a very ambitious proposal to do the very similar science, so So I guess the takeaway here is lots of effort going on in a number 09:07:53 of areas and I think that it's, there's a lot of enthusiasm in the community that you know we form sort of this sort of consortium that that you have seen in in Lego and Virgo, where it's really helpful to be able to compare data across these different 09:08:11 experiments and so I think that the, that would be really amazing if such a thing could be done with this atomic technology as it progresses and certainly all the different efforts can can learn from each other. 09:08:23 And so, so let me talk a little bit about me just so me just me just 100 is is a, we call it detector prototype. It's a 100 meter scale machine. It's a prototype for future kilometer scale machines, it's just what you would need as I said, to do gravitational 09:08:40 wave science. 09:08:43 And so matrices is to be installed at formula. There's an existing 100 meter vertical shaft from one of the neutrino VM experiments that we're going to take advantage of and install Adam interferometer along the length. 09:08:59 And we're going to use three atom sources strontium Adam sources at one bottom what is the middle and with the top. And this, you know, will be able to do the three science areas that I that I mentioned before, graduate science, which relates dark matter 09:09:16 and also extremely quantum superposition states where we're hoping to drop atoms for many seconds and aim for larger than meters scale, we've packaged separation, and while the items are in free fall. 09:09:28 In, while the atoms are in freefall, I should say this is a collaboration of nine institutions, so it's a really sort of learning how to move from certain kind of atomic physics scale, not only in size but also in terms of collaboration where at least 09:09:42 in my experience, it's usually smaller groups of or single group of worth of effort and here, where it's really helpful to start having groups from a number of institutions participate in a larger scale experiment so we're really learning from from the 09:09:59 particle physics experiment community. And the participants at very lab had a lot of experience with managing these larger scale collaboration so that's something that is, I think, important for moving. 09:10:09 These, these scaling up these detectors ultimately to the sides that are necessary to do a full scale gravitational wave detector, for example, I'm so I'm. 09:10:20 So, um, so here's some some engineering some sort of schematics of what makes 100 will look like. This is the meters x axis shaft that I that I'd mentioned for the 100 meter vertical shaft you can see sort of a little bit of light at the bottom. 09:10:32 So, we're going to install the atom interferometer right along this wall here. 09:10:37 You can see kind of a schematic of bed in the middle where insulation in the in the shaft is at the top of it here. 09:10:45 We have the laser lab nearby, we send late from high power laser system into this vertical vacuum pipe and send it down to the items, there are three of these Adam sources. 09:10:58 Located at as excited about three points along the shaft. 09:11:03 And we may just 100 is based on a modular design so this is one of the modules. 09:11:08 And they're about six meters long. Each we stack, a bunch of these end to end and these each are basically a vacuum chamber with magnetic shielding other support systems, and we can then install them and to end to build the whole home chain, and that 09:11:24 effort is, is the design is quite mature now and we're hoping to start building over the course of the next year, and installing. 09:11:34 So terms of sensitivity. 09:11:36 I got got both gravitational wave and dark matter coupling shown on the slide. 09:11:42 So, first off on the left gravitational wave sensitivity, what can you do with me just 100. So me just wanted as I said this is a prototype machine it's not long enough, likely to detect gravitational waves, you, we expect that require kilometers skill 09:11:57 instrument, but it's possible to do a lot of interesting work on gravitational wave science, basically, in the spirit of understanding how to build larger detectors and learn what would be required to ultimately scale up that says that sensitivity is 09:12:10 shown here, you live on the right Lisa on the left, and then you can see in blue the in the mid van range where may just works. 09:12:20 This top line here is using, assuming current state of the art effort in terms of. In particular, the, the atom optics, how we split the atoms wave function using multiple pulses flight and and current atom flux numbers that have been demonstrated. 09:12:37 But we actually think there's a lot of room for improvement in that, even at may just 100 at this 100 meter scale, where we can enhance the sensitivity both by using higher higher flux out of sources to reduce shot noise and increasing the beam splitter 09:12:51 momentum to increase the space time area the interferometer is, and also potentially incorporating quantum entanglement to reduce shot noise. So, so all those together allow you to in principle push this down by several orders of magnitude. 09:13:04 So it's we see majors 100 really is a development effort, not only to demonstrate scaling up to it from 10 meters 200 meters, but also to try to implement some of these enhancements that are needed to get down to the sensitivities we imagined possible 09:13:19 in the dark, dark matter space you can see an example for this is a coupling to the electronic mass on the right here. 09:13:27 Compared to existing balance. You can you can improve that by at 121 to tourism agency with with reasonable parameters that we think we can get started with current state of the art results, and then also this is a, an example but the mind itself coupling. 09:13:40 This will be a differential force measurement that we would use two different isotopes strontium for this measurement and where you can you can see some large range where we can improve beyond existing balance. 09:13:53 I won't spend too much time on this but but one of the directions, going to carry on after me just 100 is to scale up to a kilometer baseline on the earth, where we haven't you know you can you can certainly find mine shafts that are vertical line chats 09:14:08 with with several kilometers of length that could be used for that. But another exciting opportunity would be to do this in space where you have the flexibility of using a much longer baseline. 09:14:18 And so this is a concept for that that we've thought a lot about where you can use to set to spacecraft separated by. 09:14:23 In this case, for this example design over 10 to the seven meters, a baseline and using sort of physically realizable parameters for the admin from a tree. 09:14:34 You can get really exciting sensitivities I'll show on the next slide this takes advantage of so called header nine link concept which is analogous to Lisa works, where you basically synthesize the baseline measurement between the two atoms. 09:14:47 By measuring it by using sort of an optical ranging between the spacecraft combined with the atom measurements. 09:14:54 So this is kind of a summary of where this can go in terms of gravitational waves sensitivity projecting into the future, both for terrestrial and space space gravitational waves etc So, so the same plot once again showing like on the right, least on 09:15:09 the left and the mid band here, and when you can see is that for for a kilometer scale instrument and in green here, you can get really exciting sensitivities that are enough to see sources that have already been seen for example this red car was the 09:15:22 first black hole binary that was seen by Lego. 09:15:26 And then in space, it's possible to do quite well so this black curve shows, so called broadband sensitivity curve. It's also possible to increase the sensitivity using resonant detection, this is what would be called dynamical the coupling sequences 09:15:42 that add coupling sequences in the atomic clock literature, where you do multiple pulses at a fixed frequency to look for a narrowband response so that's these dashed lines, you can sort of zoom in on a particular frequency range and get down to this 09:15:56 brown sensitivity curve. 09:15:58 So there's a lot of potential for gravitational waves science here. I want to I want to say that there's there's an important background called gravity gradient noise shown here in orange, which probably limits terrestrial detectors below fraction of 09:16:09 hurts. And that's where you really would want to go into space. 09:16:15 Okay so, so the development path here I think that there's a number of areas of tech in the in the number technology areas where we want to push so this chart sort of shows where we think things can go. 09:16:27 So, current state of the art is 10 meters scale, using sort of roughly 100 HRK a minimum transfer in terms of how far we can split the next wave function. 09:16:36 That's what's been demonstrated already. And so, there's a number so that's one of the areas where we think we can make a big improvement, increasing the large amount of transfer Adam optics by a couple orders of magnitude would give you a factor of 100 09:16:49 and sensitivity improvement in gravitational waves. And then the other other way forward, would be as I mentioned, increasing the number of atoms and using quantum entanglement which both, we see as a potentially giving up two factor of 10 each in the 09:17:03 future. And so, so there's basically a lot of work to do, to, to, sort of, reach these goals, but we think this is what's physically possible in the future detector. 09:17:15 I think I'm pretty much running at a time. So I may have to cut this short I don't know. 09:17:20 I'll maybe spend a minute or two, because I wanted to mention, since it's such an important part of the development effort, I want to say a word or two about large amount of transfer Adam optics and so they work my group has been doing on that, it'll 09:17:31 just be a quick summary though given the time. So, we're talking about using strontium atoms to do a major style detectors where we have these single photon transitions, such as the Iranian clock transition. 09:17:44 And there's actually another so that's, you know, primarily motivated by the reduced coupling to laser noise that you can get immediate style grading younger. 09:18:03 of transfer out of interferometer in conventional alkali atoms, were these two photon transitions. Typical the tunings from the excited state are limited, or 10. 09:18:07 gigahertz, and that sets a scale for how much spontaneous submission loss you get from this far to 10 state. 09:18:14 In, these are the equivalent limit and strontium is really exciting because the separation to the nearest excited state where you have spontaneous motion that's substantial is hundreds of terahertz away. 09:18:24 And so there's a big suppression in the spontaneous missionary. And so, you know, the current state of the art as I mentioned is about hundred sequential pulses limited by spontaneous submission, we see a path forward towards many times larger than that 09:18:39 at least theoretically you could do. Hundreds of thousands or up to a million pulses if that was the only limit. So that's really exciting direction and so we set out to test this out. 09:18:46 Last year, and we're working on. 09:18:49 Actually intermediate line transitions at triple p one state for the experts, this is sort of a, not the Long live state but has sort of kilohertz line with, which is sort of a nice intermediate range for testing these, these single photon transitions, 09:19:02 and we did a large amount of transfer sequence where you can see a sequence of pulses here on the bottom. And we can split the atoms wave function by a larger and larger amount depending on many levels is that we were able to do, and and just to summarize 09:19:14 this was the first demonstration of a large amount of transfer out of Iran are using a clock transition that we're aware of, and we're able to push out to over 100 HRK, which actually exceeded the state of the art by any other method. 09:19:27 So the first demonstration, but it worked. It was it was it was quite effective so we're able to actually set a new limit, even though was the first time that had been done so that's really promising we see avenues towards moving this out by another factor 09:19:41 of maybe 10. Hopefully in the near future. 09:19:44 We also did a green yellow letter, which is sort of a differential between to Adam interferometer is very much in the spirit of what majors would be based on, and that worked as expected. 09:19:55 So, so let me end by just outlining sort of what I see as a number of challenges and open questions. 09:20:01 First off, we're scaling right now from 10 meters 200 meters. But, and so we're learning a lot in that process there's obviously going to be a lot of challenges moving from 100 meters, two o'clock or scale or hoping that we learn now will be useful on 09:20:14 that next push for space based detectors there's a huge whole nother topic there about how do you qualify this technology and develop it so that space of space ready. 09:20:24 How do you include quantum entanglement spin squeezing in the sensors is still an open question. It's very very exciting but very challenging. 09:20:33 There's a need to develop higher flux atom sources if we really want to push down to the sensory levels, pushing out to 1000 a spark a momentum transfer and Adam interferometry is something my group is really very interested in focusing on and as I mentioned 09:20:46 some of the gravity greedy noise issue. I didn't really talk about it much but there are their ideas for how can we mitigate that we can. 09:21:03 So thanks thanks a lot for your time. 09:21:06 So, let me in there and just wanted to make sure who knows all the institutions as I said on majors 100, and all the folks that are involved that. 09:21:06 Thanks, that was extremely interesting. 09:21:09 So as before. Can we start by raising hands who has a question. 09:21:14 Okay, Jake. 09:21:16 Jason thank you so much for that. Really interesting and great progress, obviously in not just taking this idea for but trying to really implement some of the key ingredients, I guess, you know, speaking very simply, It seems a lot like what you're describing 09:21:32 from Vegas is is really a measurement system for the gradient and acceleration. 09:21:38 Am I missing something. 09:21:41 That's. 09:21:42 You can absolutely think about it as, as a differential acceleration measurement, if you think about the automatic in a conventional three poles admin a proper sequence it's an accelerometer and if you take the difference of that you'd be sensitive to 09:21:52 gravity gradient and so that would be like a DC effect you would see difference and the difference of gravity and height on some either you know, you can talk about gravitational waves, for example, the number of ways in one. 09:22:05 One way to talk about it would be a time during grabbed a gradient, that's that's one language you could use in a particular gauge. 09:22:11 So, so we're looking for time varying differential accelerations, and then we can extend that further for the residents sequences are in a dynamic decoupling sequence there you're not sensitive to to the acceleration, but rather just more higher derivatives 09:22:24 if you like an emotion. 09:22:26 Ultimately, looking at you can really zoom in on a particular sign your social isolation if you want, of the motion. 09:22:36 So then my follow up question. Yes, one. What is your advice for it hurts you're projecting for the next generation and Magnus. 09:22:43 Yeah, that's right. So, so that's so I guess I'm a little hesitant to give the numbers at flash parameters, the ratio the differential differential acceleration over the meaning celebration so this is the parameter used to characterize equivalents principal 09:22:55 test. 09:22:58 And the big difference between majors and and sort of a DC equals personal test is we're really focusing on time varying, so a military differential accelerations. 09:23:09 And it's a lot harder to make a DC measurement than an AC measurement in some ways, you know we for example, there, there can be there can be a differential acceleration that's fixed in time, that would, you know, look like a violation of the equivalence 09:23:21 principle but wouldn't be in our target frequency range so we could we wouldn't have to worry about systematic errors that are slowly bearing, we can focus on systematic errors in our in our range of interest. 09:23:44 know quite quite good, better than 10 to the minus 15 G. Just as a rough idea at a particular frequency for the sort of extreme numbers that I gave from ages where you're talking about multiple seconds and drop time. 09:23:50 Essentially, I don't know if that answers your question so I'm not trying to dodge. We really don't want to do a DC measurement, because that is much harder. 09:23:58 So for example if there were, if there's a magnetic field background for example that causes that that will cause the energy levels of the item to shift and that might be different at the to Adam services that will look like and that will look like an 09:24:09 effective differential phase shift between the two frontrunners but if it's constant in time. It's not very in our target range, then we can reject that so so that that makes it a lot easier to design the apparatus by focusing on. 09:24:21 Okay, to read it back to you what I heard you say is your targeting attend to them is 15 over about 10 seconds of integration time for the sensitivity of individual interferometer in setting. 09:24:32 So that would be for a single drop time on the order of several seconds of drop time. Yeah. 09:24:40 Yeah. So in her per shot. Yeah, that's really impressive obviously given that state of the art admin Frommer's or more attentive minus 12. 09:24:47 Yeah, so the larger drop times, give you a lever on that sensitivity and the large amount of transfer Adam optics they were talking about also scale up that sensitivity so it's a combination of these two so state of the art comes from some measurements 09:25:04 using some like 10 inch bar km optics in for a factor of 100 by going 2000 HRK, and a factor of 10 by longer drop times you can do. Yeah, so, and I'm being a little bit rough here because there's a range of differential equations that we hope to get to 09:25:19 get to these these dark. 09:25:31 That's right I did a couple of unique users. The reason I asked all these questions is because what you described is something that's going to fall under export controls. I'm curious what the path forward is there any way. Well, right so are there right 09:25:36 Right. So are there right so I guess the maybe the military applications are a little bit unclear for defense applications for 100 meter installation but so but yeah i think that the sensitivity is pretty exciting. 09:25:47 And we, I guess remote mostly focused on these fundamental physics applications so I don't anticipate that to be too much trouble and I guess, as I said, I really hope that there's a good international collaboration where we can share technology ideas 09:25:59 in this area so hopefully that doesn't doesn't come in. 09:26:03 Next. 09:26:05 Okay next I believe was Lance. 09:26:08 Thanks a lot for a very interesting talk isn't probably a naive question but I noticed that your frequency range was more or less dictated by the drop time. 09:26:19 And if there were any interest in going to lower frequencies, is there a way to, you know, maintain the phase information by sort of juggling that is tossing ABS at different times and carrying it across and and and then I would need to understand what's 09:26:33 the gravity gradient noise in terms of the, you know, you said it was cutting out that region. Could you comment on that, please. Yeah sure, so that's that's great. 09:26:41 Yeah, absolutely. I think that you can certainly imagine doing these sorts of juggling schemes. 09:26:48 And it's a, I guess the it's always important when you so the, the idea is certainly sound, we thought a little bit about that. The challenges whenever you you touch the atom, you have to worry about how that influences the measurement. 09:27:00 And so, so for example, the limit of juggling would be to just just confined the items you could you could track the atoms in some potential. 09:27:08 But then extent that you put the atom in a trap the atom is no longer an inertial reference right the idea here, of having the atom be freely falling is really critical for how the sensor works. 09:27:24 It's only subject to gravitational forces if we've done a good job right so really wanted to be freely flowing particle and so if you're if you're trapping it. 09:27:28 Now, what you're you know the emotion of that Adam is dictated by the stability of whatever the trap is. And so this is really what I can say a big difference between an optical lattice clock and an admin from it for example with the word lattice buck 09:27:41 you're originally connected to the lattice and therefore to the rest of the world and so you have to. So you no longer are you no longer have an inertial reference. 09:27:55 And so I'm not talking about trapping and I was just talking about tossing them at different times and trying to you know struggle and Carrie. 09:28:00 I was, I was I'm Forgive me, I'm just sorry, thinking that it's been a juggling sequence is somewhere in between, in my mind where you're periodically pulsing on some for your clients unforced periodically to toss the atoms up again and so if you do that 09:28:15 in a clever way you may be able to do it without perturbing this inertial reference idea but you have to be really careful so I'm saying so so that would be one constraint but but yeah I think the idea is really exciting. 09:28:25 In terms of going to lower frequencies on Earth, you mentioned gravity gradient noise so this orange band here is a rough estimate of what that is it's very site dependent. 09:28:33 It turns out so what this is is a freebie falling, Adam is is is is exciting from from because it's it's decoupled from from vibration always to a large extent. 09:28:45 So if you think about Lego there's a tremendous effort to decouple the test masses from the earth using isolation status and and and you need to the same thing here but the atoms in freefall, you don't need a pendulum right it's just the couple and however 09:28:58 there's still an interruption which is the motion of nearby mass, due to size or noise the dirt is shaking around constant back and back and coupled to the atom via gravity and if you can't you can feel that and so that's what grabbing Grady noises it's 09:29:12 is just time during Newtonian gravity dude is shaking mass new the earth, near the source for from the earth and under the atom, and it, it would be difficult to go below probably fraction of hurts, based on you know naive projections now there there 09:29:27 are some ideas for how you can possibly mitigate that and that's actually motivates why may just uses three Adam services so I showed this this picture here we have bottom source of the bottom middle and the top in principle you only need one of the top 09:29:40 and the bottom that's the majors concept. The reason we put one in the middle is potentially reject gravity gradient noise and here the idea is the Newtonian forces. 09:29:50 Very like one of our our potential verse like one of our our force like one of our r squared so there can be a position dependence associated with a Newtonian background, whereas a gravitational wave very much as a planar expectation and so, in principle, 09:30:01 you could you could imagine looking for curvature across the baseline or maybe if you had an array of many Adam sources along the link you could look for higher derivatives of this, and use that to correlate those sources with with the greater noise and 09:30:15 subtracted measure and subtract. And so there that maybe let you push the gravity great noise down by perhaps a factor of 10 or so to get slightly lower frequencies but for them to go much much lower and it's going to be difficult on on the earth and 09:30:28 you probably want to go into a satellite mission. 09:30:34 Okay, we've had a couple of people patiently waiting, Luke calc Caldwell is next, I believe. 09:30:40 Hi. Alright, thanks very much talk. 09:30:57 Mine's kind of a technical question I was wondering whether you could say a little bit about vacuum. How good does the vacuum, need to be and is that challenging in a in 100 meter or a kilometer long, long tube and I'm also wondering whether you need 09:30:59 vacuum in between the atom sources. 09:31:03 Great question. Yeah, so the vacuum that we're targeting is low 10 to the minus 11 mil bar range so, which is kind of the typically what we, what we have in our 10 meter scale machines, extending that 200 meters is challenging, but the team are working 09:31:20 with a Fermilab has experienced doing exactly that, in a particle physics context. So we, and that they assured us that they've done it before and that it's relatively straightforward and and essentially technically we have will have iron pumps, every 09:31:34 five meters basically to help ensure that. 09:31:37 And then your second question was about Genie vacuum between the atom sources and not a principle so if the atom sources are localized to certain regions of the, of the vacuum pipe, where you have really good vacuum, and then the vacuum was not so good. 09:31:50 Another is that you could get away with that, in principle, in majors 100, we're trying to make the entire hundred meters shaft at this 10 to the minus 11 tour range, and that's to give us sort of 10 second time lifetimes that were longer so we don't 09:32:05 see a substantial loss of atoms. During these long duration freefall times. And you can imagine the most efficient experiment you might do and the launch Adams from the bottom of majors. 09:32:15 And you can imagine launching the entire height so launching the atoms from the bottom having to travel up and down. That would be over nine second freefall time. 09:32:22 And so we want vacuum that would support that scaling up to a kilometer it's not clear that you need the whole kilometer machine to be that epic, and you might be able to get away with some regions where the, where the pressure was not as good. 09:32:35 Thank you. 09:32:37 Okay, let's see, earlier to Tanya Rousey had her hand up a Tony Are you still there and do you still have a question. 09:32:46 Oh sure, but I think it was sort of answered in a previous question, I was just going to ask why gravity gradient noise isn't a problem in space, but I think that covered. 09:32:57 If you want to expand on that. 09:32:58 It actually is somewhat still problems with any ideas any shaking mass can cause a time very acceleration that you have to worry about. And in space. The advantages you're far away from the earth so you don't have to worry about the size of noise of the 09:33:11 earth. 09:33:12 But the spacecraft itself exerts a gravitational force on the atom and and that oil on the, on any inertial sensor that you have and this is the case and Lisa as well and so you have to make sure that the moat need that the sort of any anonymous motion 09:33:28 of the spacecraft spacecraft itself is not inertial it's subject to all sorts of non inertial forces, potentially, and those perturbations can cause differential noise on the animated film or, in this case, and so, You usually have to make sure the satellites 09:33:44 not moving too much. 09:33:46 It looks like it doesn't require extremely good control like you wouldn't pretend to be probably, you may be able to get away without using a drag free control system for example, using a major style detector which would be a huge advantage over over 09:34:00 other other likely select concepts where you need directly control, but still the motion of the satellite itself is the analogous effect. 09:34:12 Good following up on this space question What about other aspects of the space environment for instance charged particles. 09:34:18 Are they a problem at these yes yeah so so they're the, they're, I guess the concern can be well I guess there's a charge particles are when we have the atoms in I guess a picture of this but in a vacuum can to keep them protected from. 09:34:50 can't find this slide, but the idea for this would be to put, put the out of society, an enclosed vacuum chamber where they're protected for many of the, you know, second for the solar in for example it's protected from from light from the sun. 09:34:52 And as we think it's possible to keep the items that have been a meter scale region inside of inside of the satellite so to get away from that. 09:35:00 In Lisa there's an issue where you, you have to worry about the fact that the proof mass may build up a small charge. There's active compensation of the proof masses charge to serve it to zero because if you have a charge obviously that's a potential 09:35:14 electromagnetic force that could perturb the test mass atoms are nice neutral atoms are nice and that that's not a concern if if an atom were to take on another charge, we would have lots of ways to reject that it would no longer be a strontium Adam would 09:35:30 be an eye on now or something. So we wouldn't worry about that. So proof mass charging is not an issue with an atom interferometer. 09:35:38 Good. Thank you. 09:35:40 Okay, we're now going to our more general discussion periods so anyone who wants to raise questions having to do with the top two talks we just heard, or for that matter anything else. 09:35:54 Yeah, we heard several people yeah good Anna Maria, when they saw him. So do you mind telling us about them and you're measuring entanglement so I introducing his penis squeezing squeezing the system, then you can tell us a little bit of any direction 09:36:08 or how you're trying to do so do or is this in the short term or is really the long term goal or what are they. 09:36:16 I mean, yes, what is what is the possibility that this being a squeezing good, a good hair, or could be implemented by yourself the question for me right. 09:36:24 Yeah, so I think the problem is are really, really exciting. I didn't mean to downplay it too much I guess the. 09:36:37 The idea is that we'd hope to leverage, a lot of the work that's been going on and the community already in this area. So, as you know, the state of the art in that has been in rubidium Adams, there's going to be a spin squeezing spin shown in Metro Metro 09:36:46 Metro logically relevant squeezing I should say. And so, effort right now at Stanford is towards basically transferring those same techniques which is sort of this is like a cavity base squeezing demonstration in the castle which group would be to transfer 09:37:01 those that approach to the strontium system cannot freefall so and then as you have your way to scramble the faces if you're not completely uniform that's the problem and you know I think there there are, I think that the the idea would be to still be 09:37:16 able to do free fall and so that's that's actually work, I think, ongoing is to show that you can you can you can use. Use a cavity squeezing protocol and then, and then take the atoms and let them fall out of that, and then still make it so make the 09:37:31 same major scheme I've been scrubbing freely falling Adams and taking advantage of the, of the entanglement you can get in the cavity. So, but I really can't say too much about how that will actually look in majors like where the, where we would need 09:37:45 to put the cavities in the atom source or in as part of the detection, as part of the tech or presumably, so it would require a redesign of how the atom source and detection area works for sure to incorporate the the Academy where the squeezing can take 09:38:02 place. And so that's, you know, I think of it a little bit more longer term, but, but the idea i think is compatible with these certain freely falling Adams, that I described. 09:38:15 Okay, great. And the other quick question is, m well in the clocks. One of the major complications that we have will again with disease drop this is not improved quality system is that they even though the lifetime of single atom single atoms can be well, 09:38:31 well, depends on droopy one I think it's a set in microseconds. I mean, 7.5 kilohertz. 09:38:39 But we find that Coalition's between the United States, relax the sample very quickly so that's why a young to the one the largest was the ideal case when you have one item per side. 09:38:52 So, do you think that these type of, or you're going to operate in such a dilute sample that this is not a acquisition or do you think that at some point is can be also a limitation. 09:39:02 That's a great question. I think it's it's something that we thought some about but it is definitely, you know, an open questions if you haven't done, long times. 09:39:13 But, yeah, the idea would be to operate at a very very delicate sample Where were the occasional defacing would be would be reduced so that hasn't been shown at the time skills that were interested in, but you know the rough estimate suggests that that 09:39:27 that wouldn't be a driver. So I guess that's one of the things we hope to show it both with the, with the 10 meter machine the mic. 09:39:37 With with strontium atoms that it was building out and then eventually images but but yeah so the basically use a low, low, low enough density where cultural shifts so it's not just crucial defacing we worry about but also, you know, you gotta shift to 09:39:50 the clock energy level that due to the minefield and that and then you would worry about time during density could cause time during shifts that which over the systematic error, maybe in the frequency band of interest. 09:40:02 So, if every if every sample had a different number of atoms that's very dangerously in the, in the, in the, in the frequencies we're trying to find the sample right once every second or so. 09:40:11 So it's a real concern, but the idea would be to use him, mainly to mitigate by using very low density and so in particular, the cooling protocol would involve after laser cooling and prop and most likely evaporated cooling. 09:40:26 A Matter with lensing phase where we actually intentionally expand the cloud. 09:40:30 And then column eight it at a low density to. so that would be without decreasing Face Face and see but decreasing velocity and increasing size, which is good for both for two reasons right then you're less be spending less quickly and, and you're less 09:40:43 less dense, 09:40:45 looking for it could be very exciting than see yes 09:40:52 yeah more questions and discussion. 09:41:02 Great talk I do have a question, you talk mostly about gravitational waves in terms of the physics or astrophysics applications. What about kinds of new physics, I think we'll probably heard about that from Peter Green this afternoon, or sorry after the 09:41:15 break. But can you say anything about new physics capabilities of your devices. Sure, absolutely. So, so I mentioned. Maybe, maybe not enough about the prospects for for looking for scalar and vector coupled Dark Matter agenda for that that yeah so so 09:41:45 And I guess, close a couple other two areas where there's there's there's at least two majors we can look for two mechanisms one would be energy shifts. 09:41:47 that would be new physics that we can see even with majors 100 so major one is large, is long enough to is long enough to see in a new parameter range that hasn't been explored these potential candidates. 09:41:54 So we plan on using two different isotopes of strontium for some of these measurements co falling in the same ensemble and looking for at least in this case time varying EP violet equivalence principle by letting forces. 09:42:05 It would vary. 09:42:13 And so, you know, equivalence principle measurements are really great for generic tests for, you know, fairly generic tests, beyond a certain new physics because you can look for anything if I have a lot of thing most you know most new physics would tend 09:42:38 violate the principle and so you can look for in this case time bearing effects, due to maybe a dark matter field. And then anyway that I mentioned also the long basically then sort of the long duration admin Frommer's in a large way peg separation also. 09:42:44 also. That'd be new physics as well certainly if you saw any any any breakdown of traditional quantum mechanics that would be quite, quite novel, so so basically looking for studying to parents and anomalous D coherence in sort of macroscopic our human 09:42:59 scale out of interpreters. 09:43:02 Right. 09:43:03 I guess I would call that the proof of principle equivalents for quantum entanglement there are some very worthwhile to test I think. 09:43:13 Great. Okay. Who else has a question comment suggestion grand vision 09:43:23 on any subject. Uh, yeah. 09:43:27 Yes. So how would you test what you just mentioned D coherence. 09:43:35 Well I guess a good idea would be the by operating the admin or from it or with a duration of over five seconds, let's say and and and by splitting the atomic wave function by distances of over a meter, we will be operating in in a regime where, you know, 09:43:54 a superposition state that's persisting for a very long time or or over a long distance in a regime that hadn't been explored before and so textbook quantum mechanics says nothing interesting should happen and we should just be able to see straightforward 09:44:05 quantum interference, and you know, constructive and destructive interference of the matter wave wave packets over such long durations and distances but potentially, there could be new physics, where quantum mechanics breaks down says, For example spontaneous 09:44:20 localization theory where you know there's some possibility that the atoms that such a superstitious superstition state will just decay and localize into one or the other. 09:44:29 And in that case, you wouldn't be able to see interference anymore so that would be just the loss of the interference signal anomalous lost interference and now there of course, many classical ways that that can happen to. 09:44:41 And so, we would be able to basically put a bound. If we put if we did see something and almost that we couldn't explain by another mechanism that would be an interesting direction to person forever. 09:44:51 Thank you. 09:44:54 Oh, okay Holger, you have your hand up, go ahead. 09:44:58 I'm sorry I had to admit. 09:45:00 This was a wonderful talk Jason and I'm particularly excited to hear about the recent results from your lap, but had a question about the proposed gravitational wave detector. 09:45:10 It just my understanding that getting a gravitational wave sensitivity online off about 10 to the minus 17 per route hurts over 100 hertz baseline. 09:45:21 Essentially a monster reading out atomic clocks given by the strontium production sessions at a level of 10 to the minus 23 or 24. Per root hurts. And this exceeds current capabilities drastic and Lisa. 09:45:34 Wonder what your thoughts are maybe my estimates are off. 09:45:41 Yeah, so, yeah, I'm not sure about those numbers. 09:45:48 But let's just focus on that on, I'm quite agreement is certainly that the. It's the sensitivity we're talking about is beyond state of the art atomic clocks. 09:45:59 So if you take state of their atomic clocks and translate that into gravity's with sensitivity it's, we would need to go beyond that. And so, so yes this is definitely you know part of the development path I was describing. 09:46:11 On that last slide. And so, the areas where we hope to improve our primarily in the area of of large amount of transfer Adam optics, where we can get an enhancement there. 09:46:25 And, and in terms of flux and squeezing so I guess the difference between a clock and and majors, is you know we're not as concerned with accuracy. 09:46:36 So there's stability and accuracy. And so we're primarily talking about stability here increasing. 09:46:43 You want to make the analogy, two o'clock. And so, sort of DC air in the clock frequency is something you wouldn't perturb the measurement that we're talking about we're be more sensitive to things in the, in the frequency band of interest. 09:46:59 So, so yeah so that's where we aren't totally analogous two o'clock, and that makes things a little bit less ambitious but no it's certainly there's there's a number of orders of magnitude of improvement between where we are now in atomic clocks and admin 09:47:18 function where we would want to be, but as we heard yesterday there's exciting prospects for even clocks getting to 10 to the minus 20 in the relatively near future and I think that that those are improvements benefit the animated film showcase as well. 09:47:31 So I guess. 09:47:45 But But I guess I think I might take issue with exactly the number of maybe we could work it out but, but I think the there's there's three to four domains and improvement that we're hoping in the editor from her to go from state of the art to what we 09:47:47 would need so that's certainly true. 09:47:49 That's fine we're supposed to be audacious at this meeting. 09:47:52 Jesse we're just about out of time we do owe you a break, Lance Do you have something very quick here. Yeah, I think it's pretty quick. It's just when you're making the dark matter ultra light, dark matter bounder measurements versus gravitational waves 09:48:06 that happening at the same time or do you have to run into the dedicated mode for the two cases, it says, it can be in the same in the same mode for for one of the two dark matter, access to the directions that I mentioned so for the energy shifts there, 09:48:23 it's the same mode, where we're building we're offering the gradiometer with the hundred meter baseline. And that's actually the gravitational wave detector and as a dark matter probe there there's another style Dark Matter pro we can, we can do where 09:48:35 we used to isotopes co located from a single atom source, and that would be not sensitive gravitational waves so you can alternate between those two modes if you want to look for sort of equivalents principle violating differential forces that would be, 09:48:49 but but but if you're operating gravitational wave mode you are looking for. 09:48:55 For actually wide variety of dark matter couplings that shift the energy levels. But are you looking at the differential between the two groups are you just looking inside one of the groups for the, for the in the in the gravitational wave detector mode 09:49:07 you're looking for your it's not differential with isotope so this is really shifting of using a single isotope in both locations, and the mechanism there is you're basically you since you're interrogating the these two atoms, separated by you know the 09:49:22 baseline, you know you you are targeting the energy level at slightly different times, different by the light travel time. And so if the, if a dark matter field, the couple's to the atom is is oscillating in time, the some instantaneous energy level of 09:49:39 the atom will be different at the time of arrival of the light and in the two cases and so you see that differential in the in the in the face. 09:49:47 So so that so that that signal you can see with the gravitational wave texture mode. If you want to look for a differential force that couples differently to the isotopes, then you need to use two different isotopes the same time. 09:49:57 Thank you.