Topologically protected charge transfer along the edge of a chiral $\textit{p}$-wave superconductor

TL;DR

This paper analyzes the full counting statistics of charge transfer along the edge of a chiral p-wave superconductor, revealing universal, quantized current fluctuation signatures that are robust against disorder and decoherence.

Contribution

It provides the first calculation of the full counting statistics for Majorana edge modes, showing a trinomial distribution and universal even-order current correlators.

Findings

Charge transfer exhibits trinomial statistics at low temperatures.

Even-order current correlators have universal quantized values.

Electrical signatures are robust against disorder and decoherence.

Abstract

The Majorana fermions propagating along the edge of a topological superconductor with $p_x+ip_y$ pairing deliver a shot noise power of $\frac{1}{2}\times e^2/h$ per eV of voltage bias. We calculate the full counting statistics of the transferred charge and find that it becomes trinomial in the low-temperature limit, distinct from the binomial statistics of charge-$e$ transfer in a single-mode nanowire or charge-$2e$ transfer through a normal-superconductor interface. All even-order correlators of current fluctuations have a universal quantized value, insensitive to disorder and decoherence. These electrical signatures are experimentally accessible, because they persist for temperatures and voltages large compared to the Thouless energy.