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Updated: Aug 8, 2026

Angle-resolved Photoemission Spectroscopy At Ultra-low Temperatures
Published on: October 9, 2012
Andreev reflection at high magnetic fields: evidence for electron and hole transport in edge states
1Universität Regensburg, Institut für Experimentelle und Angewandte Physik, Regensburg, Germany.
Abstract:
We have studied magnetotransport in arrays of niobium filled grooves in an InAs/Al(x)Ga(1-x)Sb heterostructure. The critical field of up to 2.6 T permits one to enter the quantum Hall regime. In the superconducting state, we observe strong magnetoresistance oscillations, whose amplitude exceeds the Shubnikov-de Haas oscillations by a factor of about 2, when normalized to the background. Additionally, we find that above a geometry-dependent magnetic field value the sample in the superconducting state has a higher longitudinal resistance than in the normal state. Both observations can be explained with edge channels populated with electrons and Andreev-reflected holes.
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