Tunnelling across a nanowire

• Published in: Nature (London) Vol. 484; no. 7394; pp. 324 - 325
• Main Author: Bezryadin, Alexey
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 19-04-2012; Nature Publishing Group
• Subjects: 639/301/357/1016; 639/766/483/1139; 639/766/483/481; Humanities and Social Sciences; Indium; multidisciplinary; news-and-views; Quantum theory; Science; Science (multidisciplinary); Superconductors; Wire
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/484324b

The observation of a phenomenon known as coherent quantum phase slip, across a nanowire in a superconducting system, paves the way for applications in quantum computing and metrology.
See Letter
p.355
Coherent quantum phase slip revealed
Coherent quantum phase slip (CQPS) has not, until now, been observed experimentally. It is a phenomenon exactly dual to the Josephson effect, but whereas the latter is a coherent transfer of charges between superconducting contacts, CQPS is a coherent transfer of vortices or fluxes across a superconducting wire. This paper reports direct observation of CQPS in a strongly disordered indium oxide superconducting wire inserted in a loop; the effect manifests through the superposition of quantum states with different fluxes. The CQPS may — like the Josephson effect before it — lead to innovative applications in superconducting electronics and quantum metrology.