  Comparing the results of exact quantum calculations and those obtained from
the EBK-like quantization scheme of Silvestrov et al [Phys. Rev. Lett. 90,
116801 (2003)] we show that the spectrum of Andreev billiards of mixed phase
space can basically be decomposed into a regular and an irregular part,
similarly to normal billiards. We provide the first numerical confirmation of
the validity of this quantization scheme for individual eigenstates and discuss
its accuracy.

Mesoscale and Nanoscale Physics;Superconductivity