Transient Dynamics of d-wave Superconductors after a Sudden Excitation

TL;DR

This paper studies the ultrafast transient behavior of d-wave superconductors after a sudden change in interaction strength, revealing faster dynamics due to nodal quasiparticles and aligning with recent experimental observations.

Contribution

It provides an analytical description of gap dynamics in d-wave superconductors post-quench, highlighting the role of gap nodes in dissipation and spectral weight reduction.

Findings

Superconducting gap quickly stabilizes at a smaller value after quench.

Nodal quasiparticles introduce a dissipation channel, speeding up dynamics.

Analytical expression matches experimental spectral weight reduction.

Abstract

Motivated by recent ultafast pump probe experiments on high-temperature superconductors, we discuss the transient dynamics of a d-wave BCS model after a quantum quench of the interaction parameter. We find that the existence of gap nodes, with the associated nodal quasiparticles, introduces a dissipation channel which makes the dynamics much faster than in the conventional s-wave model. For every value of the quench parameters, the superconducting gap rapidly converges to a stationary value smaller than the one at equilibrium. Using a sudden approximation for the gap dynamics, we find an analytical expression for the reduction of spectral weight close to the nodes, which is in qualitative agreement with recent experiments.