Emergence of Larkin-Ovchinnikov-type superconducting state in a voltage-driven superconductor

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Kawamura, Taira, Ohashi, Yoji, Stoof, H. T. C.
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911793285169152
author Kawamura, Taira
Ohashi, Yoji
Stoof, H. T. C.
author_facet Kawamura, Taira
Ohashi, Yoji
Stoof, H. T. C.
contents We theoretically investigate a voltage-biased normal metal-superconductor-normal metal (N-S-N) junction. Using the nonequilibrium Green's function technique, we derive a quantum kinetic equation, to determine the superconducting order parameter self-consistently. The derived equation is an integral-differential equation with memory effects. We solve this equation by converting it into a system of ordinary differential equations with the use of a pole expansion of the Fermi-Dirac function. When the applied voltage exceeds the critical value, the superconductor switches to the normal state. We find that when the voltage is decreased from the normal phase, the system relaxes to a Larkin-Ovchinnikov (LO)-type inhomogeneous superconducting state, even in the absence of a magnetic Zeeman field. We point out that the emergence of the LO-type state can be attributed to the nonequilibrium energy distribution of electrons due to the bias voltage. We also point out that the system exhibits bistability, which leads to hysteresis in the voltage-current characteristic of the N-S-N junction.
format Preprint
id arxiv_https___arxiv_org_abs_2401_04684
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Emergence of Larkin-Ovchinnikov-type superconducting state in a voltage-driven superconductor
Kawamura, Taira
Ohashi, Yoji
Stoof, H. T. C.
Superconductivity
Quantum Gases
We theoretically investigate a voltage-biased normal metal-superconductor-normal metal (N-S-N) junction. Using the nonequilibrium Green's function technique, we derive a quantum kinetic equation, to determine the superconducting order parameter self-consistently. The derived equation is an integral-differential equation with memory effects. We solve this equation by converting it into a system of ordinary differential equations with the use of a pole expansion of the Fermi-Dirac function. When the applied voltage exceeds the critical value, the superconductor switches to the normal state. We find that when the voltage is decreased from the normal phase, the system relaxes to a Larkin-Ovchinnikov (LO)-type inhomogeneous superconducting state, even in the absence of a magnetic Zeeman field. We point out that the emergence of the LO-type state can be attributed to the nonequilibrium energy distribution of electrons due to the bias voltage. We also point out that the system exhibits bistability, which leads to hysteresis in the voltage-current characteristic of the N-S-N junction.
title Emergence of Larkin-Ovchinnikov-type superconducting state in a voltage-driven superconductor
topic Superconductivity
Quantum Gases
url https://arxiv.org/abs/2401.04684