Spin-orbit interaction driven dimerization in one-dimensional frustrated magnets

Abstract

We study the effect of spin-orbit interaction on one-dimensional U(1)-invariant frustrated magnets with dominant critical nematic fluctuations. The spin-orbit coupling explicitly breaks the U(1) symmetry of arbitrary global spin rotations about the high-symmetry axis down to Z 2 (invariance under a π-rotation). Given that the nematic order parameter is invariant under a π-rotation, it is relevant to ask if other discrete symmetries can be spontaneously broken. Here we demonstrate that the spin-orbit coupling induces a bond density wave that spontaneously breaks the translational symmetry and opens a gap in the excitation spectrum.

Thermodynamics of a frustrated quantum magnet on a square lattice

“…The AF and spin-nematic phases have competing order parameters, and therefore the transition between them has to be first order. In the transverse geometry, the spin-nematic phase should not exist in a field due to a lack of axial symmetry [32]. However, this is not supposed to impede the associated fluctuations completely.…”

Electron spin resonance in spiral antiferromagnet linarite: Theory and experiment

“…The observed biaxial anisotropy in linarite leaves two possibilities: a multipolar state can be described either by m = 1 and, thus, have the trivial dipolar symmetry or by m = 2 corresponding to a nontrivial quadrupolar state. The quadrupolar state can additionally break the transla-tion symmetry producing spontaneous dimerization [52]. Whether such a state is realized in linarite in the narrow high-field region with H b remains to be seen.…”