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Title: Point-contact Andreev reflection spectroscopy on Bi 2 Se 3 single crystals

In order to study how Andreev reflection (AR) occurs between a superconductor and a three-dimensional topological insulator (TI), we use superconducting Nb tips to perform point-contact AR spectroscopy at 4.2 K on as-grown single crystals of Bi 2Se 3. Scanning tunneling spectroscopy and scanning tunneling microscopy are also used to characterize the superconducting tip and both the doping level and surface condition of the TI sample. Furthermore, the point-contact measurements show clear spectral signatures of AR, as well as a depression of zero-bias conductance with decreasing junction impedance. The latter observation can be attributed to interfacial Rashba spin-orbit coupling, and the presence of bulk bands at the Fermi level in our samples suggests that bulk states of Bi2Se3 are involved in the observed AR.
Authors:
 [1] ;  [1] ;  [2] ;  [2] ;  [3]
  1. Univ. of Toronto, ON (Canada). Dept. of Physics
  2. Brookhaven National Lab. (BNL), Upton, NY (United States). Condensed Matter Physics and Materials Science Dept.
  3. Univ. of Toronto, ON (Canada). Dept. of Physics; Canadian Inst. for Advanced Research, Toronto ON (Canada)
Publication Date:
Report Number(s):
BNL-112626-2016-JA
Journal ID: ISSN 0217-9792; R&D Project: PM016; KC0201050
Grant/Contract Number:
SC00112704
Type:
Accepted Manuscript
Journal Name:
International Journal of Modern Physics B
Additional Journal Information:
Journal Volume: 30; Journal Issue: 13; Journal ID: ISSN 0217-9792
Publisher:
World Scientific
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Andreev reflection; topological insulator; superconductor
OSTI Identifier:
1336146