Superconducting terminals as sensitive probes for scarred states.
When a quantum-chaotic normal conductor is coupled to a superconductor, the random-matrix theory (RMT) predicts that a gap opens up in the excitation spectrum which is of universal size E(g)(RMT) approximately 0.3 Planck/t(D), where t(D) is the mean scattering time between Andreev reflections. We show that a scarred state of long lifetime t(S)>>t(D) suppresses the excitation gap over a window DeltaE approximately 2E(g)(RMT) which can be much larger than the narrow resonance width GammaS= Planck/t(S) of the scar in the normal system. The minimal value of the excitation gap within this window is given by GammaS/2<<E(g)(RMT). Via this suppression of the gap to a nonuniversal value, the scarred state can be detected over a much larger energy range than it is in the case when the superconducting terminal is replaced by a normal one.
Kormányos
Andor
A
Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom.
Schomerus
Henning
H