Majorana oscillations modulated by Fano interference and dregree of non-locality in a topological superconducting nanowire-quantum dot system

TL;DR

This paper theoretically investigates how Fano interference affects Majorana oscillations in a topological superconducting nanowire-quantum dot system, revealing how non-locality influences conductance features and enabling estimation of Majorana non-locality.

Contribution

It introduces a model analyzing the interplay of Fano interference and Majorana oscillations, providing insights into how non-locality impacts conductance patterns in hybrid nanostructures.

Findings

Fano interference modulates Majorana oscillations in conductance.

Resonant conditions produce fractional Fano-like resonances.

Conductance profiles reveal signatures of Majorana non-locality.

Abstract

We explore theoretically the influence of Fano interference in the so-called Majorana oscillations in a T-shaped hybrid setup formed by a quantum dot (QD) placed between conducting leads and side-coupled to a topological superconducting nanowire (TSNW) hosting zero-energy Majorana bound states (MBSs) at the ends. Differential conductance as a function of the external magnetic field reveals oscillatory behavior. Both the shape and amplitude of the oscillations depend on the bias-voltage, degree of MBSs non-locality and Fano parameter of the system determining the regime of interference. When the latter is such that direct lead-lead path dominates over lead-QD-lead path and the bias is tuned in resonance with QD zero-energy, pronounced fractional Fano-like resonances are observed around zero-bias for highly non-local geometries. Further, the conductance profiles as a function of both bias-voltage and QD energy level display "bowtie" and "diamond" shapes, in qualitative agreement with both previous theoretical and experimental works. These findings ensure that our proposal can be used to estimate the degree of MBS non-locality, thus allowing to investigate their topological properties.