Majorana-mediated thermoelectric transport in multiterminal junctions

TL;DR

This paper investigates how Majorana zero modes influence thermoelectric transport in multiterminal junctions, revealing distinctive conductance signatures and violations of the Wiedemann-Franz law that can aid in their detection.

Contribution

It demonstrates that Majorana zero modes cause significant enhancements in conductance and thermopower, and violate the Wiedemann-Franz law, providing new thermoelectric detection methods for MZMs.

Findings

Enhanced electrical and thermal conductance at specific phase differences due to MZMs

Strong violation of Wiedemann-Franz law in the presence of MZMs

Robustness of signatures against Cooper pair splitting processes

Abstract

The unambiguous identification of Majorana zero modes (MZMs) is one of the most outstanding problems of condensed matter physics. Thermal transport provides a detection tool that is sensitive to these chargeless quasiparticles. We study thermoelectric transport between metallic leads transverse to a Josephson junction. The central double quantum dot hosts conventional or topological Andreev states that depend on the phase difference $\phi$. We show that the presence of MZMs can be identified by a significant amplification of both the electrical and thermal conductance at $\phi \approx \pi$ as well as the Seebeck coefficient at $\phi \approx 0$. In addition, we show that the Wiedemann-Franz law is strongly violated in the presence of MZMs around $\phi \approx \pi$ when compared to the conventional case. We further investigate the robustness of our results against Cooper pair splitting processes.