Dependence of Andreev Reflection and Schottky Barriers on Gamnas/Nb Interface Treatment
Publication Type
Original research
Authors
  • D. Dahliah
  • K. F. Eid
  • H. A. Abujeib
  • X. Liu
  • J. K. Furdyna
Fulltext
Download

We studied the interfacial contact between GaMnAs and superconducting Nb micro-structures both with and without removing the native GaMnAs surface oxide. Our results show that a strong Schottky barrier forms at the interface when the oxide layer is left between Nb and GaMnAs. This barrier can be confused for Andreev Reflection and erroneously used to extract spin polarization. A simple acid etch is shown to remove the oxide film, thus decreasing the interface resistance, removing the Schottky barrier, and causing a clear Andreev reflection effect. One key recommendation for point contact Andreev reflection studies is to push the tip hard enough into contact and verify that the total resistance is not too high.

Journal
Title
J. Appl. Phys. 117, 17E104
Publisher
--
Publisher Country
Palestine
Publication Type
Both (Printed and Online)
Volume
--
Year
2015
Pages
--