Anatomy of point-contact Andreev reflection spectroscopy from the experimental point of view (review)

Abstract

We review application of point-contact Andreev-reflection spectroscopy to study elemental superconductors, where theoretical conditions for the smallness of the point-contact size with respect to the characteristic lengths in the superconductor can be satisfied. We discuss existing theoretical models and identify new issues that have to be solved, especially when applying this method to investigate more complex superconductors. We will also demonstrate that some aspects of point-contact Andreev-reflection spectroscopy still need to be addressed even when investigating ordinary metals.

20 pages, 18 figs. V2: Ref.60 and footnote 3 are added, a number of minor fixes

References in corpus (7)

• The role of critical current on point contact Andreev Reflection spectrum between a normal metal and a superconductor
• Evidence of gap anisotropy in superconducting YNi2B2C using directional point contact spectroscopy
• Distribution of conduction channels in nanoscale contacts: Evolution towards the diffusive limit
• Competition of multiband superconducting and magnetic order in ErNi2B2C observed by Andreev reflection
• Direct observation of ballistic Andreev reflection
• Experimental verification of contact-size estimates in point-contact spectroscopy on superconductor/ferromagnet heterocontacts
• Mechanisms of normal reflection at metal interfaces studied by Andreev-reflection spectroscopy

Cited by in corpus (9)

• Evidence for nematic superconductivity of topological surface states in PbTaSe2
• Surface superconductivity in the Weyl semimetal MoTe2 detected by point contact spectroscopy
• Electron-phonon interaction and point contact enhanced superconductivity in trigonal PtBi2
• Control over epitaxy and the role of the InAs/Al interface in hybrid two-dimensional electron gas systems
• Dominant $s$-wave superconducting gap in PdTe${}_2$ observed by tunneling spectroscopy on side-junctions
• Enhanced critical temperatures in the strongly overdoped iron-based superconductors AFe${}_2$As${}_2$ (A = K, Cs, Rb) observed by point contacts
• Sub-kelvin Andreev reflection spectroscopy of superconducting gaps in FeSe
• Superconductivity in hole-doped germanium point contacts
• Nonequilibrium effects in ballistic point contacts Ta-Cu and 2H-NbSe2-Cu. Two-gap superconductivity in 2H-NbSe2