Giant shot noise from Majorana zero modes in topological trijunctions

TL;DR

This paper demonstrates that Majorana zero modes in topological trijunctions cause giant shot noise, providing a potential experimental signature for their identification in transport measurements.

Contribution

It reveals that Majorana bound states at trijunctions lead to giant shot noise, highlighting a new experimental signature for Majorana detection.

Findings

Majorana zero modes cause giant shot noise at low voltages.

Shot noise amplitude is sensitive to contact transparency.

Dephasing from Andreev reflections limits noise measurements.

Abstract

The clear-cut experimental identification of Majorana bound states in transport measurements still poses experimental challenges. We here show that the zero-energy Majorana state formed at a junction of three topological superconductor wires is directly responsible for giant shot noise amplitudes, in particular at low voltages and for small contact transparency. The only intrinsic noise limitation comes from the current-induced dephasing rate due to multiple Andreev reflection processes.