Break-junction technique in application to layered superconductors (Review article)

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 Mg${}_{1-x}$Al${}_x$B${}_2$ compounds.

55 pages, 17 figures

References in corpus (9)

• Band filling and interband scattering effects in MgB${}_2$: C vs Al doping
• Al substitution in MgB2 crystals: influence on superconducting and structural properties
• High-pressure flux growth, structural, and superconducting properties of LnFeAsO (Ln = Pr, Nd, Sm) single crystals
• High Temperature Superconductivity in Transition Metal Oxypnictides: a Rare-Earth Puzzle?
• Th substituted SmFeAsO: structural details and superconductivity with Tc above 50 K
• Anion height dependence of Tc and density of states in iron based superconductors
• Lower critical field and SNS-Andreev spectroscopy of 122-arsenides: Evidence of nodeless superconducting gap
• Transfer-matrix approach to multiband Josephson junctions
• Investigation of LiFeAs by means of "Break-junction" Technique

Cited by in corpus (5)

• Amplitudes of minima in dynamic conductance spectra of the SNS Andreev contact
• On the Structure of Superconducting Order Parameter in High-Temperature Fe-Based Superconductors
• Superconducting Order Parameter and Bosonic Mode in Hydrogen-Substituted NdFeAsO${}_{0.6}$H${}_{0.36}$ Revealed by Multiple Andreev Reflection Spectroscopy
• Direct Evidence of Two Superconducting Gaps in FeSe${}_{0.5}$Te${}_{0.5}$: SnS-Andreev Spectroscopy and Lower Critical Field
• Direct observation of the spin exciton in Andreev spectroscopy of iron-based superconductors