Coulomb blockade of chiral Majorana and complex fermions far from equilibrium

TL;DR

This paper analyzes charge transport in a single-electron transistor with chiral Majorana or Dirac edge modes, revealing differences in high-voltage offset currents and oscillation patterns due to particle-hole symmetry.

Contribution

It provides an asymptotic solution for high-voltage transport in Majorana and Dirac cases, highlighting key differences in current behavior and oscillation patterns.

Findings

Majorana case shows up to 50% higher offset current.

Distinct oscillation patterns of current as a function of gate charge.

Particle-hole symmetry affects the distribution function in Majorana systems.

Abstract

We study charge transport in a single-electron transistor implemented as an interferometer such that the Coulomb blockaded middle island contains a circular chiral Majorana or Dirac edge mode. We concentrate on the regime of small conductance and provide an asymptotic solution in the limit of high transport voltage exceeding the charging energy. The solution is achieved using an instanton-like technique. The distinctions between Majorana and Dirac cases appears when the tunnel junctions are unequal. The main difference is in the offset current at high voltages which can be higher up to $50\%$ in Majorana case. It is caused by an additional particle-hole symmetry of the distribution function in the Majorana case. There is also an eye-catching distinction between the oscillations patterns of the current as a function of the gate charge. We conjecture this distinction survives at lower transport voltages as well.