Manipulating Andreev and Majorana Bound States with microwaves

TL;DR

This paper investigates how microwave pulses influence Andreev and Majorana bound states at superconductor boundaries, revealing a method to unambiguously identify Majorana states via differential conductance measurements.

Contribution

It introduces a novel approach using microwave radiation to manipulate and distinguish Andreev and Majorana bound states in superconductor junctions.

Findings

Microwave pulses induce dynamical phase shifts in bound states.

The method provides a clear signature of Majorana states in conductance.

Microwave control can differentiate between Andreev and Majorana states.

Abstract

We study the interplay between Andreev (Majorana) bound states that form at the boundary of a (topological) superconductor and a train of microwave pulses. We find that the extra dynamical phase coming from the pulses can shift the phase of the Andreev reflection, resulting in the appear- ance of dynamical Andreev states. As an application we study the presence of the zero bias peak in the differential conductance of a normal-topological superconductor junction - the simplest, yet somehow ambiguous, experimental signature for Majorana states. Adding microwave radiation to the measuring electrodes provides an unambiguous probe of the Andreev nature of the zero bias peak.