Laboratoire de Physique Théorique
Toulouse - UMR 5152

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 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. 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.

[1] Liu & Ye, arXiv:2410.03607