Topological thermoelectric effects in spin-orbit coupled electron and hole doped semiconductors

TL;DR

This paper analyzes the intrinsic Berry-phase contributions to anomalous Hall and Nernst effects in spin-orbit coupled semiconductors, identifying topological regimes via characteristic plateaus and peaks in transport coefficients.

Contribution

It reveals how topological superconducting states can be identified through specific features in Hall and Nernst coefficients in doped semiconductors with spin-orbit coupling.

Findings

Plateaus in Hall and Nernst coefficients indicate topological regimes.

Peaks in coefficients mark the emergence of topological states.

Results aid experimental identification of topological regimes.

Abstract

We compute the intrinsic contributions to the Berry-phase mediated anomalous Hall and Nernst effects in electron- and hole-doped semiconductors in the presence of an in-plane magnetic field as well as Rashba and Dresselhaus spin orbit couplings. For both systems we find that the regime of chemical potential which supports the topological superconducting state in the presence of superconducting proximity effect can be characterized by plateaus in the topological Hall and Nernst coefficients flanked by well-defined peaks marking the emergence of the topological regime. The plateaus arise from a clear momentum space separation between the region where the Berry curvature is peaked (at the `near-band-degeneracy' points) and the region where the single (or odd number of) Fermi surface lies in the Brillouin zone. The plateau for the Nernst coefficient is at vanishing magnitudes surrounded by two peaks of opposite signs as a function of the chemical potential. These results could be useful for experimentally deducing the chemical potential regime suitable for realizing topological states in the presence of proximity effect.