Dynamical quantum phase transitions in a mesoscopic superconducting system

We inspect signatures of dynamical quantum phase transitions driven by two\ntypes of quenches acting on a correlated quantum dot embedded between\nsuperconducting and metallic reservoirs. Under stationary conditions the\nproximity induced on-dot pairing combined with the strong Coulomb repulsion\nprefers the quantum dot to be either in the singly occupied (spinful) or\nBCS-type (spinless) ground state configuration. We study the time evolution\nupon traversing such a phase boundary due to quantum quenches by means of the\ntime-dependent numerical renormalization group approach, revealing non-analytic\nfeatures in the low-energy return rate. Quench protocols can be realized in a\ncontrollable manner and we are confident that detection of this dynamical\nsinglet-doublet phase transition would be feasible by the charge tunnelling\nspectroscopy.\n