Thermoelectric fluctuations of interfering Majorana bound states

Nonequilibrium states produced by electric and thermal voltages $(V,{V}_{T})$ provide a straightforward insight into the underlying degrees of freedom of composite nanostructures, and they are of particular interest to probe Majorana bound states. Here we explore fluctuations of thermoelectric currents at finite frequencies $\ensuremath{\omega}$ in a quantum dot coupled to two interfering Majorana bound states. At small $V$ we find that in the emission spectra, the differential thermoelectric quantum noise $\ensuremath{\partial}{S}^{>}/\ensuremath{\partial}{V}_{T}$ shows an antiresonance, whereas in the absorption spectra Majorana interference induces an antiresonance-resonance pair. At large $V$ this pair is preserved, whereas the emission antiresonance turns into an antiresonance-resonance pair identical to the absorption one making $\ensuremath{\partial}{S}^{>}/\ensuremath{\partial}{V}_{T}$ antisymmetric in the frequency $\ensuremath{\omega}$. This antisymmetry distinguishes Majorana behavior from the one induced by Andreev bound states and does not break at higher temperatures, making it attractive for experiments on Majorana interference via thermoelectric fluctuation response.