A topological crystalline response theory for quantum paramagnets

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 result [1] on the Lieb-Schultz-Mattis (LSM) constraints for quantum paramagnets and topological crystalline response theory underlying these constraints. The topological crystalline responses contain important information about symmetry, excitations, and lattice defects, applicable to all 3D quantum paramagnets. I will highlight 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.