Andreev bound states in superconductor/ferromagnet point contact Andreev reflection spectra
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
As charge carriers traverse a single superconductor ferromagnet interface, they experience an additional spin-dependent phase angle that results in spin mixing and the formation of a bound state called the Andreev bound state. Here we explore whether point contact Andreev reflection can be used to detect the Andreev bound state and, within the limits of our experiment, we extract the resulting spin mixing angle. By examining spectra taken from
L
a
1.15
S
r
1.85
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n
2
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7
−
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junctions, together with a compilation of literature data on highly spin polarized systems, we suggest that the existence of the Andreev bound state would resolve a number of long standing controversies in the literature of Andreev reflection, as well as defining a route to quantify the strength of spin mixing at superconductor-ferromagnet interfaces. Intriguingly, we find that for high transparency junctions, the spin mixing angle appears to take a relatively narrow range of values across all the samples studied. The ferromagnets we have chosen to study share a common property in terms of their spin arrangement, and our observations may point to the importance of this property in determining the spin mixing angle under these circumstances.
L
a
1.15
S
r
1.85
M
n
2
O
7
−
Pb
junctions, together with a compilation of literature data on highly spin polarized systems, we suggest that the existence of the Andreev bound state would resolve a number of long standing controversies in the literature of Andreev reflection, as well as defining a route to quantify the strength of spin mixing at superconductor-ferromagnet interfaces. Intriguingly, we find that for high transparency junctions, the spin mixing angle appears to take a relatively narrow range of values across all the samples studied. The ferromagnets we have chosen to study share a common property in terms of their spin arrangement, and our observations may point to the importance of this property in determining the spin mixing angle under these circumstances.
Date Issued
2017-03-22
Date Acceptance
2017-02-09
Citation
Physical Review B, 2017, 95 (9)
ISSN
2469-9950
Publisher
American Physical Society
Journal / Book Title
Physical Review B
Volume
95
Issue
9
Copyright Statement
© 2017 American Physical Society. K. A. Yates, L. A. B. Olde Olthof, M. E. Vickers, D. Prabhakaran, M. Egilmez, J. W. A. Robinson, and L. F. Cohen
Phys. Rev. B 95, 094516 – Published 22 March 2017, available at https://dx.doi.org/10.1103/PhysRevB.95.094516
Phys. Rev. B 95, 094516 – Published 22 March 2017, available at https://dx.doi.org/10.1103/PhysRevB.95.094516
Sponsor
The Leverhulme Trust
Engineering & Physical Sciences Research Council (E
Grant Number
RPG-2016-306
RG81276
Publication Status
Published
Article Number
094516