Distinguishing Majorana bound states and Andreev bound states with microwave spectra

TL;DR

This paper proposes using microwave spectroscopy to differentiate Majorana bound states from trivial Andreev bound states in 1D Josephson junctions, aiding the experimental verification of Majorana fermions for quantum computing.

Contribution

The study introduces a numerical approach to distinguish MBSs from Andreev states via their unique microwave spectral responses, highlighting the robustness of MBS signatures.

Findings

Distinct microwave spectral responses for MBSs and Andreev states.

Robust fractional Josephson coupling as a signature of MBSs.

Feasible method for experimental verification of MBSs.

Abstract

Majorana fermions are fascinating and not yet confirmed quasiparticles in condensed matter physics. Here we propose using microwave spectra to distinguish Majorana bound states (MBSs) from topological trivial Andreev bound states. By numerically calculating the transmission and Zeeman field dependence of the many-body excitation spectrum of a 1D Josephson junction, we find that the two kinds of bound states have distinct responses to variations in the related parameters. Furthermore, the singular behaviors of the MBSs spectrum could be attributed to the robust fractional Josephson coupling and nonlocality of MBSs. Our results provide a feasible method to verify the existence of MBSs and could accelerate its application to topological quantum computation.