Low Temperature Physics: 42, 1008 (2016); https://doi.org/10.1063/1.4971437
Fizika Nizkikh Temperatur: Volume 42, Number 11 (November 2016), p. 1284-1310    ( to contents , go back )

Break-junction experiments on layered superconductors (Review Article)

S.A. Kuzmichev1 and T.E. Kuzmicheva2

1Lomonosov Moscow State University, Leninskie Gory, Moscow, 119991, Russian Federation
E-mail: kuzmichev@mig.phys.msu.ru

2P.N. Lebedev Physical Institute, Russian Academy of Sciences, Moscow 119991, Russian Federation
pos Анотація:

Received May 10, 2016

Abstract

Here presented a systematic study of superconductor-constriction-superconductor contacts realized by a break-junction technique in layered superconductors.Depending on the constriction transparency the tunneling and SnS-Andreev spectroscopies could be used, for the direct determination of values of superconducting gaps, characteristic BCS-ratios and gap temperature dependences in cuprate superconductors, magnesium diboride, novel pnictides and chalcogenides. Basing on these data, one can estimate the gap anisotropy magnitude as well as values of electron-boson coupling constants. We discuss the advantages and difficulties of the break-junction technique and demonstrate this method is powerful enough for high-resolution investigation of optical phonon modes in high-temperature superconducting cuprates and for creating of the contacts with the selective transparence in Mg1–xAlxB2 compounds.

PACS: 74.25.–q Properties of superconductors;
PACS: 74.45.+c Proximity effects; Andreev reflec-tion; SN and SNS junctions;
PACS: 74.50.+r Tunneling phenomena; Josephson effects;
PACS: 74.70.Xa Pnictides and chalcogenides.

Key words: break-junction, pnictides, Andreev spectroscopy, tunneling spectroscopy, two-gap superconductivity, high-temperature superconductors.

Published online: September 26, 2016

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