**
Multi-component quantum gases offer additional rich dynamics compared to single component BEC as they add the possibilities for an exchange of population between different quantum gas components - a favourable system in this respect are quantum gases with spin degree of freedom.
In this talk the magnetic properties of these spinor quantum gases as well as novel effects in the interaction of condensate fractions and normal components will be discussed. In particular we study the dynamic evolution and magnetic ground states in spinor Bose-Einstein condensates of 87Rb [1].
We present the magnetic phase diagrams in comparison to the experimental properties of 87Rb Bose-Einstein condensates in the F=1 and F=2 hyperfine states, which we interestingly find to behave ferromagnetic in the F=1 state but antiferromagnetic in the F=2 state.
For further coupling and manipulation schemes of these magnetic phases a low magnetic field mixed-spin-channel Feshbach resonance that we have studied might be well suited [2].
As a further main point we investigate different thermalisation regimes in multi component spinor systems, which allow novel studies on ‘condensate melting’ and even allow a ‘new’ realisation of BEC which does not rely on cooling down an ensemble of atoms but adding more and more particles at constant temperature to the system [3].
**

- H. Schmaljohann, M. Erhard, J. Kronjäger, M. Kottke, J.J. Arlt, K. Bongs and K. Sengstock; 'Dynamics of F=2 Spinor Bose-Einstein Condensates', Phys. Rev. Lett. 92, 040402 (2004).
- M. Erhard, H. Schmaljohann, J. Kronjäger, K. Bongs and K. Sengstock; 'Measurement of a Mixed-spin-channel Feshbach Resonance in 87Rb', Phys. Rev. A, cond-mat/0309318 (2003).
- M. Erhard, H. Schmaljohann, J. Kronjäger, K. Bongs, K. Sengstock; 'Bose-Einstein Condensation at Constant Temperature', cond-mat/0402003 (2004).

**
**
Begin WebCam and audio for the whole talk: high bandwidth or medium bandwidth.

Or, begin audio only for the whole talk:
high bandwidth or low bandwidth.
(Or, right-click to download the whole audio file.)

Begin QuickTime of the whole talk (high bandwidth).

To begin viewing slides, click on the first slide below. (Or, view as pdf.)