Relaxation Dynamics of Photoinduced Changes in the Superfluid Weight of High-Tc Superconductors

TL;DR

This paper investigates the transient photoinduced changes in the superfluid weight of high-Tc superconductors, revealing nonexponential decay at low temperatures due to phonon absorption, challenging previous quasiparticle recombination models.

Contribution

It derives a new formula linking nonlinear response to nonequilibrium distribution and numerically demonstrates nonexponential decay caused by phonon absorption.

Findings

Nonexponential decay at low temperatures observed.

Decay driven by phonon absorption, not quasiparticle recombination.

Provides a new theoretical framework for transient superfluid dynamics.

Abstract

In the transient state of d-wave superconductors, we investigate the temporal variation of photoinduced changes in the superfluid weight. We derive the formula that relates the nonlinear response function to the nonequilibrium distribution function. The latter qunatity is obtained by solving the kinetic equation with the electron-electron and the electron-phonon interaction included. By numerical calculations, a nonexponential decay is found at low temperatures in contrast to the usual exponential decay at high temperatures. The nonexponential decay originates from the nonmonotonous temporal variation of the nonequilibrium distribution function at low energies. The main physical process that causes this behavior is not the recombination of quasiparticles as previous phenomenological studies suggested, but the absorption of phonons.