Quantum interferences in bismuth nanowires based Josephson junctions: signature of topological ballistic edge states?
CFM Seminars
- Speaker
-
Helen Bouchiat (Laboratoire de Physique des Solides, Université Paris Sud)
- When
-
2016/04/08
14:00 - Place
- Donostia International Physics Center (DIPC)
- Add to calendar
- iCal
"Quantum interferences in bismuth nanowires based Josephson junctions:
signature of topological ballistic edge states?"
Anil Murani, Alik Kasumov, Sophie Guéron, Richard Deblock
and Hélène Bouchiat
LPS, CNRS Univ. Paris Sud, Université Paris Saclay 91405 Orsay
We investigate proximity induced superconductivity in micrometer-long single
crystal bismuth nanowires connected to superconducting electrodes with a high
critical field. At low temperature we measure a supercurrent that persists in
magnetic fields as high as the critical field of the electrodes. The critical
current is also strongly modulated by the magnetic field. In certain samples
we find regular, rapid periodic oscillations occurring up to high fields.
Other samples exhibit less periodic but full modulations of the critical
current on Tesla field scales, with field-caused extinctions of the
supercurrent. These findings indicate the existence of low dimensionally,
phase coherent, interfering conducting regions through the samples.
We relate these results to the electronic properties of the (111) surface
states of bismuth with strong Rashba spin-orbit coupling. In particular recent
experiments in SQUID geometry reveal the contribution of ballistic edge states
along the nanowires.