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arXiv · 2112.10126

Dynamical quantum phase transitions in a mesoscopic superconducting system

Kacper Wrześniewski·Ireneusz Weymann·Nicholas Sedlmayr·Tadeusz Domański
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Abstract

We inspect signatures of dynamical quantum phase transitions driven by two types of quenches acting on a correlated quantum dot embedded between superconducting and metallic reservoirs. Under stationary conditions the proximity induced on-dot pairing combined with the strong Coulomb repulsion prefers the quantum dot to be either in the singly occupied (spinful) or BCS-type (spinless) ground state configuration. We study the time evolution upon traversing such a phase boundary due to quantum quenches by means of the time-dependent numerical renormalization group approach, revealing non-analytic features in the low-energy return rate. Quench protocols can be realized in a controllable manner and we are confident that detection of this dynamical singlet-doublet phase transition would be feasible by the charge tunnelling spectroscopy.

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Kacper Wrześniewski, Ireneusz Weymann, Nicholas Sedlmayr, Tadeusz Domański. 2021-12-19. Dynamical quantum phase transitions in a mesoscopic superconducting system. https://doi.org/10.1103/physrevb.105.094514

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