Characterizing 3D quantum paramagnets using Lieb-Schultz-Mattis constraints
Chunxiao Liu (UC Berkeley)
Quantum paramagnets represent intriguing quantum phases that evade ordering even at absolute zero temperature. While detecting their presence is relatively straightforward, unraveling their fundamental nature can be a challenging task. In this talk, I will present our recent work [1] on Lieb-Schultz-Mattis (LSM) constraints which prohibit certain quantum paramagnets from being a “trivial” one. I will highlight the topological response theory underlying the LSM constraints that we developed, containing information about symmetry, excitations, and lattice defects, applicable to all 3D quantum paramagnets. I will illustrate the use of these results through two examples: (1) the prediction of a Dirac spin liquid in the triangular lattice compound NaYbO2, and (2) the characterization of U(1) quantum spin liquids in a pyrochlore S=1/2 antiferromagnet.