Andreev reflection in two-dimensional topological insulators with either conserved or broken time-reversal symmetry
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2012Access:
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Awadhesh Narayan and Stefano Sanvito, Andreev reflection in two-dimensional topological insulators with either conserved or broken time-reversal symmetry, Physical Review B, 86, 4, 2012, 041104(R)-Download Item:
PhysRevB.86.041104.pdf (Published (publisher's copy)) 3.272Mb
Abstract:
We investigate Andreev reflection in two-dimensional heterojunctions formed by a superconductor in contact
with a topological insulator ribbon either possessing or breaking time-reversal symmetry. Both classes of
topological insulators exhibit perfect Andreev reflection, which is robust against disorder. This is assigned
to topologically protected edge states. In the time-reversal symmetric case we show that doping one of the ribbon
edges with magnetic impurities suppresses one Andreev channel, while no such suppression is seen in the broken
symmetry situation. Based on this observation, we suggest a tabletop transport experiment able to distinguish
between the two types of topological insulators, which does not involve the direct measurement of the material
band structure.
Sponsor
Grant Number
Irish Research Council for Science and Engineering Technology (IRCSET)
G30479
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http://people.tcd.ie/sanvitosDescription:
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Author: SANVITO, STEFANO; NARAYAN, AWADHESH
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Physical Review B86
4
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Andreev reflectionSubject (TCD):
Nanoscience & MaterialsDOI:
http://dx.doi.org/ 10.1103/PhysRevB.86.041104Licences: