Pumped heat and charge statistics from Majorana braiding

TL;DR

This paper investigates heat and charge transport in a topological superconductor with Majorana zero modes, revealing a geometric correction to the fluctuation theorem linked to Majorana braiding that is topologically protected and robust.

Contribution

It introduces a full counting statistics approach for heat transport in a Majorana system, showing a topologically protected geometric correction to the fluctuation theorem during braiding.

Findings

Geometric correction extends to topologically protected braiding cycles.

Correction is non-vanishing in adiabatic, cyclic parameter variations.

Correction is robust against slow fluctuations of driving parameters.

Abstract

We examine the heat and charge transport of a driven topological superconductor. Our particular system of interest consists of a Y-junction of topological superconducting wires, hosting non-Abelian Majorana zero modes at their edges. The system is contacted to two leads which act as continuous detectors of the system state. We calculate, via a scattering matrix approach, the full counting statistics of the driven heat transport, between two terminals contacted to the system, for small adiabatic driving and characterise the energy transport properties as a function of the system parameters (driving frequency, temperature). We find that the geometric, dynamic contribution to the pumped heat statistics results in a correction to the Gallavotti-Cohen type fluctuation theorem for quantum heat transfer. Notably, the correction term to the fluctuation theorem extends to cycles which correspond to topologically protected braiding of the Majorana zero modes. This geometric correction to the fluctuation theorem differs from its analogs in previously studied systems in that (i) it is non-vanishing for adiabatic cycles of the system's parameters, without the need for cyclic driving of the leads and (ii) it is insensitive to small, slow fluctuations of the driving parameters due to the topological protection of the braiding operation.