Electronic nematicity refers to a strongly correlated electronic phase that breaks crystalline rotational symmetry. In a square lattice, nematicity maps onto an Ising model, as the nematic director can only choose between the x or y directions. In triangular or hexagonal lattices, nematicity maps onto a three-state Potts model. Unlike the well-known Ising nematicity, the realization and identification of three-state Potts nematicity remain an outstanding challenge. In this talk, I will present elastoresistivity measurements of two candidates for three-state Potts nematicity: kagome metals CsV3Sb5 and van der Waals layered material 1T-TiSe2. Both materials exhibit a charge density wave (CDW) transition. Previous studies suggested that CsV3Sb5 hosts a CDW-driven Potts nematicity, whereas 1T-TiSe2 hosts a chiral CDW. Contrary to these claims, our results show no nematicity in CsV3Sb5 but reveal a diverging nematic response in 1T-TiSe2. I will discuss the implications of Potts nematicity in 1T-TiSe2 and its relation to superconductivity.
Reference:
Zhaoyu Liu, Yue Shi, Qianni Jiang, Elliott W Rosenberg, Jonathan M DeStefano, Jinjin Liu, Chaowei Hu, Yuzhou Zhao, Zhiwei Wang, Yugui Yao, David Graf, Pengcheng Dai, Jihui Yang, Xiaodong Xu, Jiun-Haw Chu, “Absence of nematic instability in the kagome metal CsV3Sb5”, Physical Review X 14 (3), 031015