Photoinduced pseudospin-wave emission from charge-density-wave domain wall with superconductivity

TL;DR

This paper investigates how photoexcitation at a charge-density-wave domain wall with superconductivity can induce collective mode emission and domain wall melting, revealing complex nonequilibrium dynamics and phase transitions.

Contribution

It introduces a theoretical framework to analyze photoinduced dynamics at CDW-SC interfaces, demonstrating collective mode emission and domain wall melting phenomena.

Findings

Photo-driven SC interfaces emit collective modes of the order parameter.

High-frequency excitation causes domain wall melting and induces superconductivity system-wide.

The dynamics are analyzed using time-dependent Hartree-Fock-Bogoliubov and RPA methods.

Abstract

We study photoinduced dynamics triggered by an inhomogeneity due to competition between charge density waves (CDWs) and superconductivity. As a simple example, we consider the superconducting (SC) interface between two CDW domains with opposite signs. The real-time dynamics are calculated within the time-dependent Hartree--Fock--Bogoliubov framework, where the order parameter dynamics and the nonequilibrium quasiparticle distribution functions are studied. We also calculate the various dynamical response functions within a generalized random phase approximation. Through comparisons between the real time dynamics and the analysis of the response functions, it is found that the photo-driven SC interface can emit collective modes of the SC order parameter. This is analogous to the spin wave emission from the magnetic domain wall in an antiferromagnet, particularly in the case of a low driving frequency, where the order parameters can be mapped onto the pseudospin picture. In the high-frequency case, we find a domain wall melting caused by changes in the quasiparticle distribution, which induces superconductivity in the whole system.