Universal Current Correlations Induced by the Majorana and Fermionic Andreev Bound States

TL;DR

This paper demonstrates that both Majorana and fermionic Andreev bound states exhibit universal nonlocal current correlations in a 2D topological insulator, which are robust to system asymmetries and can serve as signatures for detection.

Contribution

It reveals the universal behavior of current correlations for both Majorana and fermionic Andreev bound states in a 2D topological insulator system.

Findings

Both bound states show nonlocality with similar coupling patterns.

Maximal cross differential CCCs are robust to structural asymmetry.

Universal current correlation characteristics can help identify Majorana states.

Abstract

Due to their nonlocality, Majorana bound states have been proposed to induce current-current correlations (CCCs) that are completely different from those induced by low-energy fermionic Andreev bound states. Such characteristics can be used as a signature to detect Majorana bound states. Herein, we studied the Majorana and fermionic Andreev bound states in a two-dimensional topological insulator system. We found that nonlocality occurs for both types of bound states and that their coupling strengths depend on system parameters in the same pattern. Majorana and fermionic Andreev bound states show the same differential CCCs characteristics, thereby indicating a universal behavior for both types of bound states. The maximal cross differential CCCs are robust to the structural asymmetry of the system.