Quantum interference due to crossed Andreev reflection in a d-wave superconductor with two nano-contacts

TL;DR

This paper theoretically investigates how crossed Andreev reflection in a d-wave superconductor with two nano-contacts leads to unique conductance resonance peaks due to Andreev bound states.

Contribution

It introduces a theoretical model for crossed Andreev reflection in a d-wave superconductor with two quantum wires, highlighting the formation of Andreev bound states and their impact on conductance.

Findings

Resonance peaks in conductance occur below the superconducting gap.

Resonance peaks are due to bonding and antibonding Andreev bound states.

The model explains conductance features for tunnel contacts.

Abstract

The crossed Andreev reflection in a hybrid nanostructure consisting of a d-wave superconductor and two quantum wires is theoretically studied. When the (110) oriented surface of the superconductor is in contact with the wires parallel and placed close to each other, the Andreev bound state is formed by the crossed Andreev reflection. The conductance has two resonance peaks well below the gap structure in the case of tunnel contacts. These peaks originate from the bonding and antibonding Andreev bound states of hole wave functions.