Quantum transport through a double Aharonov-Bohm-interferometer in the presence of Andreev reflection

TL;DR

This paper investigates quantum transport in a double Aharonov-Bohm interferometer with Andreev reflection, revealing how magnetic flux and coupling influence reflection probabilities and current peaks.

Contribution

It provides a detailed analysis of tunable Andreev reflection probabilities and oscillation periods in a double interferometer using nonequilibrium Green function methods.

Findings

Reflection probability oscillation period depends linearly on flux ratio n

Coupling strength affects peak height, linewidth, and position of Andreev reflection current

Magnetic fluxes can tune Andreev reflection current peaks

Abstract

Quantum transport through a double Aharonov-Bohm-interferometer in the presence of Andreev reflection is investigated in terms of the nonequilibrium Green function method with which the reflection current is obtained. Tunable Andreev reflection probabilities depending on the interdot coupling strength and magnetic flux as well are analysised in detail. It is found that the oscillation period of the reflection probability with respect to the magnetic flux for the double interferometer depends linearly on the ratio of two parts magnetic fluxes n, i.e. 2(n+1)pi, while that of a single interferometer is 2pi. The coupling strength not only affects the height and the linewidth of Andreev reflection current peaks vs gate votage but also shifts the peak positions. It is furthermore demonstrated that the Andreev reflection current peaks can be tuned by the magnetic fluxes.