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arXiv · 1409.7359

Spontaneous formation of a non-uniform chiral spin liquid in moat-band lattices

Tigran A. Sedrakyan·Leonid I. Glazman·Alex Kamenev
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Abstract

A number of lattices exhibit moat-like band structures, i.e. a band with infinitely degenerate energy minima attained along a closed line in the Brillouin zone. If such a lattice is populated with hard-core bosons, the degeneracy prevents their condensation. At half-filling, the system is equivalent to $s=1/2$ XY model at zero magnetic field, while absence of condensation translates into the absence of magnetic order in the XY plane. Here we show that the ground state breaks the time-reversal as well as inversion symmetries. This state, which may be identified with the chiral spin liquid, has a bulk gap and chiral gapless edge excitations. The applications of the developed analytical theory include an explanation of recent numerical findings and a suggestion for the chiral spin liquid realizations in experiments with cold atoms in optical lattices.

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Tigran A. Sedrakyan, Leonid I. Glazman, Alex Kamenev. 2015-01-23. Spontaneous formation of a non-uniform chiral spin liquid in moat-band lattices. https://doi.org/10.1103/physrevlett.114.037203

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