Point contact Andreev reflection from semimetallic bismuth-The roles of the minority carriers and the large spin-orbit coupling
Citation:
Stamenov, P., Point contact Andreev reflection from semimetallic bismuth-The roles of the minority carriers and the large spin-orbit coupling, Journal of Applied Physics, 113, 17, 2013, 17C718Download Item:

Abstract:
The Point Contact Andreev Reflection (PCAR) technique has been traditionally and predominantly
applied to either the characterisation of superconductors or of spin-polarised metals. The sufficiently
large and slowly varying, on the scale of tens of meV around the Fermi level (
E
F
), Density of States
(DOS) in metals and highly degenerate semiconductors significantly simplifies the interpretation and
quantitative analysis of the measured Differential Conductance Spectra (DCS). Semimetals in
general, and particularly the heavy semimetals, because of the presence of several carrier bands and
the larger Spin-Orbit coupling, exhibit significantly higher variations in the DOS, close to
E
F
,which
can be observed and evaluated with PCAR. Here, DCS of bismuth/niobium point contacts are
examined to reveal the relative energy offsets [0.12(3), 2.32(5), and 5.7(2)] meV and the approximate
relative DOS contributions of the three main carrier bands (16:5:4). Apart from the bulk, some
surface states are also expected to contribute to the observed DOS and be potentially spin-split. The
spin polarisation due to all conducting states is evaluated at
P
0.09(7)
Sponsor
Grant Number
Science Foundation Ireland (SFI)
NISE (10/IN1/I3002)
Science Foundation Ireland (SFI)
11/SIRG/I2130
Author's Homepage:
http://people.tcd.ie/stamenpDescription:
PUBLISHED
Author: STAMENOV, PLAMEN
Type of material:
Journal ArticleCollections:
Series/Report no:
Journal of Applied Physics113
17
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Point Contact Andreev Reflection (PCAR)DOI:
http://dx.doi.org/10.1063/1.4796049Licences: