Floquet-engineered diode performance in a Majorana-quantum dot Josephson junction

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Roy, Koustav, Paul, Gourab, Debnath, Debika, Bhattacharyya, Kuntal, Basu, Saurabh
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908520804253696
author Roy, Koustav
Paul, Gourab
Debnath, Debika
Bhattacharyya, Kuntal
Basu, Saurabh
author_facet Roy, Koustav
Paul, Gourab
Debnath, Debika
Bhattacharyya, Kuntal
Basu, Saurabh
contents We study nonreciprocal signatures of Josephson current (JC) in a quantum dot (QD)-based Josephson junction (JJ) that comprises of two periodically driven Kitaev chains (KCs) coupled with an intervening QD. The simultaneous breaking of the inversion symmetry ($\mathcal{IS}$) and the time-reversal symmetry ($\mathcal{TRS}$), indispensable for the Josephson diode effect (JDE), is achieved solely via the two Floquet drives that differ by a finite phase, which eventually results in a nonreciprocal current, and hence yields a finite JDE. It may be noted that the Floquet Majorana modes generated at both the far ends of the KCs (away from the QD) and adjacent to the QD junctions mediate the JC owing to a finite superconducting (SC) phase difference in the two KCs. We calculate the time-averaged JC and inspect the tunability of the current-phase relation (CPR) to ascertain the diode characteristics. The asymmetric Floquet drive also manifests an anomalous JC signature in our KC-QD-KC JJ. Furthermore, additional control over the QD energy level can be achieved via an external gate voltage that renders flexibility for the Josephson diode (JD) to act as an SC switching device. Tuning different system parameters, such as the chemical potential of the KCs, Floquet frequency, the relative phase mismatch of the drives, and the gate voltage, our model shows the highest possible rectification to be around $70\%$. Summarizing, our study provides an alternative scenario, replacing the traditional usage of an external magnetic field and spin-orbit coupling effects in a JD via asymmetrically driven Kitaev leads that entail Majorana-mediated transport.
format Preprint
id arxiv_https___arxiv_org_abs_2503_07428
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Floquet-engineered diode performance in a Majorana-quantum dot Josephson junction
Roy, Koustav
Paul, Gourab
Debnath, Debika
Bhattacharyya, Kuntal
Basu, Saurabh
Mesoscale and Nanoscale Physics
We study nonreciprocal signatures of Josephson current (JC) in a quantum dot (QD)-based Josephson junction (JJ) that comprises of two periodically driven Kitaev chains (KCs) coupled with an intervening QD. The simultaneous breaking of the inversion symmetry ($\mathcal{IS}$) and the time-reversal symmetry ($\mathcal{TRS}$), indispensable for the Josephson diode effect (JDE), is achieved solely via the two Floquet drives that differ by a finite phase, which eventually results in a nonreciprocal current, and hence yields a finite JDE. It may be noted that the Floquet Majorana modes generated at both the far ends of the KCs (away from the QD) and adjacent to the QD junctions mediate the JC owing to a finite superconducting (SC) phase difference in the two KCs. We calculate the time-averaged JC and inspect the tunability of the current-phase relation (CPR) to ascertain the diode characteristics. The asymmetric Floquet drive also manifests an anomalous JC signature in our KC-QD-KC JJ. Furthermore, additional control over the QD energy level can be achieved via an external gate voltage that renders flexibility for the Josephson diode (JD) to act as an SC switching device. Tuning different system parameters, such as the chemical potential of the KCs, Floquet frequency, the relative phase mismatch of the drives, and the gate voltage, our model shows the highest possible rectification to be around $70\%$. Summarizing, our study provides an alternative scenario, replacing the traditional usage of an external magnetic field and spin-orbit coupling effects in a JD via asymmetrically driven Kitaev leads that entail Majorana-mediated transport.
title Floquet-engineered diode performance in a Majorana-quantum dot Josephson junction
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2503.07428