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arXiv · 0901.3137

Microscopic theory of the Andreev gap

T. Micklitz·Alexander Altland
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Abstract

We present a microscopic theory of the Andreev gap, i.e. the phenomenon that the density of states (DoS) of normal chaotic cavities attached to superconductors displays a hard gap centered around the Fermi energy. Our approach is based on a solution of the quantum Eilenberger equation in the regime $t_D\ll t_E$, where $t_D$ and $t_E$ are the classical dwell time and Ehrenfest-time, respectively. We show how quantum fluctuations eradicate the DoS at low energies and compute the profile of the gap to leading order in the parameter $t_D/t_E$ .

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T. Micklitz, Alexander Altland. 2009-01-20. Microscopic theory of the Andreev gap. https://doi.org/10.1103/physrevlett.103.080403

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