Effect of spin-orbit coupling on the excitation spectrum of Andreev billiards

Béri, B.; Bardarson, J. H.; Beenakker, C. W. J.

Effect of spin-orbit coupling on the excitation spectrum of Andreev billiards

Authors

Béri, B.

Bardarson, J. H.

Beenakker, C. W. J.

Description

We consider the effect of spin-orbit coupling on the low energy excitation spectrum of an Andreev billiard (a quantum dot weakly coupled to a superconductor), using a dynamical numerical model (the spin Andreev map). Three effects of spin-orbit coupling are obtained in our simulations: In zero magnetic field: (1) the narrowing of the distribution of the excitation gap; (2) the appearance of oscillations in the average density of states. In strong magnetic field: (3) the appearance of a peak in the average density of states at zero energy. All three effects have been predicted by random-matrix theory.
5 pages, 4 figures