Anomalous Nernst Effect in Nonmagnetic Nodal Line Semimetal PbTaSe$_2$

X iv :2 11 2. 00 28 2v 1 [ co nd -m at .s tr -e l] 1 D ec 2 02 1 Anomalous Nernst Effect in Nonmagnetic Nodal Line Semimetal PbTaSe2 K. Yokoi, H. Murakawa, H. Sakai, and N. Hanasaki Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan Abstract PbTaSe2 is a unique topological material, in which the number of nodal lines is expected to change at the structural transition between the lower temperature/pressure “L” phase and the higher temperature/pressure “H” phase. We report the anomalous Nernst effect attributed to the Berry curvature of nodal lines and its change with the structural transition. In the L phase, the Nernst coefficient (Syx) shows the step-like magnetic field dependence reminiscent of the anomalous Nernst effect of nonmagnetic Dirac/Weyl semimetals. By applying hydrostatic pressure, we discovered that the amplitude of the anomalous component significantly decreases at the transition to the H phase, which might correspond to the partial annihilation of nodal line structures.