Population inversion and dynamical phase transitions in a driven superconductor
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 new "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.
Keywords
Cite
@article{arxiv.1808.01287,
title = {Population inversion and dynamical phase transitions in a driven superconductor},
author = {H. P. Ojeda Collado and José Lorenzana and Gonzalo Usaj and C. A. Balseiro},
journal= {arXiv preprint arXiv:1808.01287},
year = {2019}
}