Gate-tunable Josephson diode effect in Rashba spin-orbit coupled quantum dot junctions

Fuente: arXiv
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Main Authors: Debnath, Debika, Dutta, Paramita
Format: Preprint
Published: 2024
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author Debnath, Debika
Dutta, Paramita
author_facet Debnath, Debika
Dutta, Paramita
contents We theoretically explore Josephson diode effect (JDE) in superconductor/quantum dot (QD)/superconductor junction in the presence of a magnetic field and Rashba spin-orbit interaction (RSOI). We calculate the Josephson current in our QD junction using Keldysh non-equilibrium Green's function technique. We show that JDE is induced in our chiral QD junction with large rectification coefficient (RC) in the presence of RSOI and external magnetic field simultaneously. Interestingly, the sign and magnitude of the RC are highly controllable by the magnetic field and RSOI. For realistic RSOI strength in the presence of magnetic field and chirality, the RC can be tuned to be as high as $70\%$ by an external gate potential, indicating a giant JDE in our QD junction. Our proposed QD-based Josephson diode (JD) may serve as a potential superconducting device component.
format Preprint
id arxiv_https___arxiv_org_abs_2402_00817
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Gate-tunable Josephson diode effect in Rashba spin-orbit coupled quantum dot junctions
Debnath, Debika
Dutta, Paramita
Superconductivity
Mesoscale and Nanoscale Physics
We theoretically explore Josephson diode effect (JDE) in superconductor/quantum dot (QD)/superconductor junction in the presence of a magnetic field and Rashba spin-orbit interaction (RSOI). We calculate the Josephson current in our QD junction using Keldysh non-equilibrium Green's function technique. We show that JDE is induced in our chiral QD junction with large rectification coefficient (RC) in the presence of RSOI and external magnetic field simultaneously. Interestingly, the sign and magnitude of the RC are highly controllable by the magnetic field and RSOI. For realistic RSOI strength in the presence of magnetic field and chirality, the RC can be tuned to be as high as $70\%$ by an external gate potential, indicating a giant JDE in our QD junction. Our proposed QD-based Josephson diode (JD) may serve as a potential superconducting device component.
title Gate-tunable Josephson diode effect in Rashba spin-orbit coupled quantum dot junctions
topic Superconductivity
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2402.00817