2004/04/30 by J. Eroms, D. Weiss, J. De Boeck +2 · 1 citation
Physics and Astronomy · #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.95.107001
published as Phys. Rev. Lett. 95, 107001 (2005) · accepted for Phys Rev Lett, some changes to text
arxiv created 2005/07/20 · arxiv updated 2009/12/01
We have studied magnetotransport in arrays of niobium filled grooves in an InAs/AlGaSb heterostructure. The critical field of up to 2.6 T permits 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 two, 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.