skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: A missing step is a key step

Abstract

In a uniform superconductor, electrons form Cooper pairs that pick up the same quantum mechanical phase for their bosonic wavefunctions. This spontaneously breaks the gauge symmetry of electromagnetism. In 1962 Josephson predicted, and it was subsequently observed, that Cooper pairs can quantum mechanically tunnel between two weakly coupled superconductors that have a phase difference Φ. The resulting supercurrent is a 2π periodic function of the phase difference Φ across the junction. This is the celebrated Josephson effect. More recently, a fractional Josephson effect related to the presence of Majorana bound states — Majoranas — has been predicted for topological superconductors. This fractional Josephson effect has a characteristic 4π periodic current–phase relation. Now, writing in Nature Materials, Chuan Li and colleagues report experiments that utilize nanoscale phase-sensitive junction technology to induce superconductivity in a fine-tuned Dirac semimetal Bi 0.97Sb 0.03 and discover a significant contribution of 4π periodic supercurrent in Nb–Bi 0.97Sb 0.03–Nb Josephson junctions under radiofrequency irradiation.

Authors:
 [1];  [2]
  1. Univ. of Texas, Dallas, Richardson, TX (United States). Dept. of Physics
  2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Publication Date:
Research Org.:
Sandia National Lab. (SNL-CA), Livermore, CA (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1502455
Report Number(s):
SAND-2018-10061J
Journal ID: ISSN 1476-1122; 667848
Grant/Contract Number:  
AC04-94AL85000; NA0003525
Resource Type:
Accepted Manuscript
Journal Name:
Nature Materials
Additional Journal Information:
Journal Volume: 17; Journal Issue: 10; Journal ID: ISSN 1476-1122
Publisher:
Springer Nature - Nature Publishing Group
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Zhang, Fan, and Pan, Wei. A missing step is a key step. United States: N. p., 2018. Web. doi:10.1038/s41563-018-0179-1.
Zhang, Fan, & Pan, Wei. A missing step is a key step. United States. doi:10.1038/s41563-018-0179-1.
Zhang, Fan, and Pan, Wei. Mon . "A missing step is a key step". United States. doi:10.1038/s41563-018-0179-1. https://www.osti.gov/servlets/purl/1502455.
@article{osti_1502455,
title = {A missing step is a key step},
author = {Zhang, Fan and Pan, Wei},
abstractNote = {In a uniform superconductor, electrons form Cooper pairs that pick up the same quantum mechanical phase for their bosonic wavefunctions. This spontaneously breaks the gauge symmetry of electromagnetism. In 1962 Josephson predicted, and it was subsequently observed, that Cooper pairs can quantum mechanically tunnel between two weakly coupled superconductors that have a phase difference Φ. The resulting supercurrent is a 2π periodic function of the phase difference Φ across the junction. This is the celebrated Josephson effect. More recently, a fractional Josephson effect related to the presence of Majorana bound states — Majoranas — has been predicted for topological superconductors. This fractional Josephson effect has a characteristic 4π periodic current–phase relation. Now, writing in Nature Materials, Chuan Li and colleagues report experiments that utilize nanoscale phase-sensitive junction technology to induce superconductivity in a fine-tuned Dirac semimetal Bi0.97Sb0.03 and discover a significant contribution of 4π periodic supercurrent in Nb–Bi0.97Sb0.03–Nb Josephson junctions under radiofrequency irradiation.},
doi = {10.1038/s41563-018-0179-1},
journal = {Nature Materials},
number = 10,
volume = 17,
place = {United States},
year = {2018},
month = {9}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 2 works
Citation information provided by
Web of Science

Save / Share: