arXiv:1808.01287 · Physical review. B./Physical review. B

Population inversion and dynamical phase transitions in a driven superconductor

H. P. Ojeda Collado, J. Lorenzana, Gonzalo Usaj, C. A. Balseiro

Published Dec 27, 2018• 22 citations

Abstract

We consider a superconductor in which the density of states at the Fermi level or the pairing interaction is driven periodically with a frequency larger than the superconducting gap in the collisionless regime. We show by numerical and analytical computations that a subset of quasiparticle excitations enter into resonance and perform synchronous Rabi oscillations leading to cyclic population inversion with a frequency that depends on the amplitude of the drive. As a consequence a different ``Rabi-Higgs'' mode emerges. Turning off the drive at different times and modulating the strength allows access to all known dynamical phases of the order parameter: persistent oscillations, oscillations with damping and overdamped dynamics. We discuss physical realizations of the drive and methods to detect the dynamics.

DOI: 10.1103/physrevb.98.214519

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