Anomalous $h/2e$ periodicity and Majorana zero modes in chiral Josephson junctions

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Sun, Zi-Ting, Hu, Jin-Xin, Xie, Ying-Ming, Law, K. T.
Format: Preprint
Published: 2023
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910579834224640
author Sun, Zi-Ting
Hu, Jin-Xin
Xie, Ying-Ming
Law, K. T.
author_facet Sun, Zi-Ting
Hu, Jin-Xin
Xie, Ying-Ming
Law, K. T.
contents Recent experiments reported that quantum Hall chiral edge state-mediated Josephson junctions (chiral Josephson junctions) could exhibit Fraunhofer oscillations with a periodicity of either $h/e$ [Vignaud \textit{et al}.,~Nature~(2023)] or $h/2e$ [Amet \textit{et al}.,~Science~\textbf{352}~966~(2016)]. While the $h/e$-periodic component of the supercurrent had been anticipated theoretically before, the emergence of the $h/2e$-periodicity is still not fully understood. In this work, we show that the chiral edge states coupled to the superconductors become chiral Andreev edge states. In short junctions, the coupling of the chiral Andreev edge states can cause the $h/2e$-magnetic flux periodicity. Our theory resolves the long-standing puzzle concerning the appearance of the $h/2e$-periodicity in chiral Josephson junctions. Furthermore, we explain that when the chiral Andreev edge state couple, a pair of localized Majorana modes appear at the ends of the Josephson junction, which are robust and independent of the phase difference between the two superconductors. As the $h/2e$-periodicity and the Majorana zero modes have the same physical origin, the Fraunhofer oscillation period can be used to identify the regime with Majorana zero modes.
format Preprint
id arxiv_https___arxiv_org_abs_2308_01079
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Anomalous $h/2e$ periodicity and Majorana zero modes in chiral Josephson junctions
Sun, Zi-Ting
Hu, Jin-Xin
Xie, Ying-Ming
Law, K. T.
Mesoscale and Nanoscale Physics
Superconductivity
Recent experiments reported that quantum Hall chiral edge state-mediated Josephson junctions (chiral Josephson junctions) could exhibit Fraunhofer oscillations with a periodicity of either $h/e$ [Vignaud \textit{et al}.,~Nature~(2023)] or $h/2e$ [Amet \textit{et al}.,~Science~\textbf{352}~966~(2016)]. While the $h/e$-periodic component of the supercurrent had been anticipated theoretically before, the emergence of the $h/2e$-periodicity is still not fully understood. In this work, we show that the chiral edge states coupled to the superconductors become chiral Andreev edge states. In short junctions, the coupling of the chiral Andreev edge states can cause the $h/2e$-magnetic flux periodicity. Our theory resolves the long-standing puzzle concerning the appearance of the $h/2e$-periodicity in chiral Josephson junctions. Furthermore, we explain that when the chiral Andreev edge state couple, a pair of localized Majorana modes appear at the ends of the Josephson junction, which are robust and independent of the phase difference between the two superconductors. As the $h/2e$-periodicity and the Majorana zero modes have the same physical origin, the Fraunhofer oscillation period can be used to identify the regime with Majorana zero modes.
title Anomalous $h/2e$ periodicity and Majorana zero modes in chiral Josephson junctions
topic Mesoscale and Nanoscale Physics
Superconductivity
url https://arxiv.org/abs/2308.01079