Hexagonal warping induced nonlinear planar Nernst effect in nonmagnetic topological insulators
Xiao-Qin Yu, Zhen‐Gang Zhu, Gang Su
Abstract
We propose theoretically an effect, i.e., the nonlinear planar Nernst effect (NPNE), in nonmagnetic topological insulator (TI) ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$ in the presence of an in-plane magnetic field. We find that the Nernst current scales quadratically with temperature gradient but linearly with magnetic field and exhibits a cosine dependence on the orientation of the magnetic field with respect to the direction of the temperature gradient. The NPNE has a quantum origin arising from the conversion of a nonlinear transverse spin current to a charge current due to a joint result of hexagonal warping effect, spin-momentum locking, and the time-reversal symmetry breaking induced by the magnetic field.