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Andreev reflection and cyclotron motion at superconductor -- normal-metal interfaces

F. Giazotto·M. Governale·U. Zuelicke·F. Beltram
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Abstract

We investigate Andreev reflection at the interface between a superconductor and a two--dimensional electron system (2DES) in an external magnetic field such that cyclotron motion is important in the latter. A finite Zeeman splitting in the 2DES and the presence of diamagnetic screening currents in the superconductor are incorporated into a microscopic theory of Andreev edge states, which is based on the Bogoliubov--de Gennes formalism. The Andreev--reflection contribution to the interface conductance is calculated. The effect of Zeeman splitting is most visible as a double--step feature in the conductance through clean interfaces. Due to a screening current, conductance steps are shifted to larger filling factors and the formation of Andreev edge states is suppressed below a critical filling factor.

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F. Giazotto, M. Governale, U. Zuelicke, F. Beltram. 2005-04-20. Andreev reflection and cyclotron motion at superconductor -- normal-metal interfaces. https://doi.org/10.1103/physrevb.72.054518

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