Majorana-mediated thermoelectric transport in multiterminal junctions

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.