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arXiv · 1704.02838

Chirality blockade of Andreev reflection in a magnetic Weyl semimetal

N. Bovenzi·M. Breitkreiz·P. Baireuther·T. E. O'Brien·J. Tworzydlo·I. Adagideli·C. W. J. Beenakker
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Abstract

A Weyl semimetal with broken time-reversal symmetry has a minimum of two species of Weyl fermions, distinguished by their opposite chirality, in a pair of Weyl cones at opposite momenta $\pm K$ that are displaced in the direction of the magnetization. Andreev reflection at the interface between a Weyl semimetal in the normal state (N) and a superconductor (S) that pairs $\pm K$ must involve a switch of chirality, otherwise it is blocked. We show that this "chirality blockade" suppresses the superconducting proximity effect when the magnetization lies in the plane of the NS interface. A Zeeman field at the interface can provide the necessary chirality switch and activate Andreev reflection.

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N. Bovenzi, M. Breitkreiz, P. Baireuther, T. E. O'Brien, J. Tworzydlo, I. Adagideli, C. W. J. Beenakker. 2017-04-10. Chirality blockade of Andreev reflection in a magnetic Weyl semimetal. https://doi.org/10.1103/physrevb.96.035437

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