Andreev reflection and enhanced subgap conductance in NbN/Au/InGaAs-InP junctions

I. E. Batov; Th. Schaepers; A. A. Golubov; A. V. Ustinov

doi:10.1063/1.1783612

Andreev reflection and enhanced subgap conductance in NbN/Au/InGaAs-InP junctions

Mesoscale and Nanoscale Physics 2009-11-10 v2

Authors: I. E. Batov , Th. Schaepers , A. A. Golubov , A. V. Ustinov

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Abstract

We report on the fabrication of highly transparent superconductor/normal metal/two-dimensional electron gas junctions formed by a superconducting NbN electrode, a thin (10nm) Au interlayer, and a two-dimensional electron gas in a InGaAs/InP heterostructure. High junction transparency has been achieved by exploiting of a newly developed process of Au/NbN evaporation and rapid annealing at 400C. This allowed us to observe for the first time a decrease in the differential resistance with pronounced double-dip structure within the superconducting energy gap in superconductor-2DEG proximity systems. The effect of a magnetic field perpendicular to the plane of the 2DEG on the differential resistance of the interface was studied. It has been found that the reduced subgap resistance remains in high magnetic fields. Zero-field data are analyzed within the previously established quasiclassical model for the proximity effect.

Keywords

Andreev reflection superconductor normal metal 2DEG subgap conductance magnetic field proximity effect

Cite

@article{arxiv.cond-mat/0309682,
  title  = {Andreev reflection and enhanced subgap conductance in NbN/Au/InGaAs-InP junctions},
  author = {I. E. Batov and Th. Schaepers and A. A. Golubov and A. V. Ustinov},
  journal= {arXiv preprint arXiv:cond-mat/0309682},
  year   = {2009}
}

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15 pages, 5 figures

Andreev reflection and enhanced subgap conductance in NbN/Au/InGaAs-InP junctions

Abstract

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