Schedule Nov 23, 2020
Spontaneously broken lattice symmetry in a novel quantum spin liquid of spin-1 moments
Andriy Nevidomskyy, Rice
Cite as: doi:10.26081/K68K6G

Quantum spin liquids are known to arise in strongly frustrated spin systems as a result of competing interactions. Here we consider a spin-1 model on a square lattice, where despite the absence of geometric frustration, competition between the nearest neighbor Heisenberg (J) and biquadratic (K) interactions results in a quantum spin liquid around the J = K point, as evidenced by our density matrix renormalization group (DMRG) studies. At that point, the model has an emergent SU(3) symmetry and our calculations based on N = 3 flavor- wave theory indicate the presence of large quantum fluctuations that destabilize the nearby antiferromagnetic and quadrupolar orders. What emerges is a quantum spin liquid with no long-range order in spin or quadrupolar channels, which nevertheless has fluctuations peaked at the wavevector (π, 2π/3) and spontaneously breaks the C4 rotational symmetry of the square lattice [1]. We demonstrate, by considering an anisotropic square lattice, that this lattice-nematic spin liquid is distinct from the limit of weakly coupled Haldane chains. Analysis of the spectral gaps and entanglement entropy is consistent with the spin liquid being either gapless or having a very small gap.

[1] W.-J. Hu et al, PRB 100, 165142 (2019).

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