Title

Impact of damping on the superconducting gap dynamics induced by intense terahertz pulses

Campus Units

Physics and Astronomy, Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

8-5-2019

Journal or Book Title

Physical Review B

Volume

100

Issue

5

First Page

054504

DOI

10.1103/PhysRevB.100.054504

Abstract

We investigate the interplay between coherent gap dynamics and damping in superconductors taken out of equilibrium by strong optical pulses with subgap terahertz frequencies. A semiphenomenological formalism is developed to include the damping within the electronic subsystem that arises from effects beyond Bardeen-Cooper-Schrieffer mean-field theory, such as interactions between Bogoliubov quasiparticles and decay of the Higgs mode. These processes, conveniently expressed as longitudinal T1 and transverse T2 relaxation times in the standard pseudospin language for superconductors, cause the gap amplitude to be suppressed after the pulse is turned off, but before the timescale where thermalization occurs due to coupling to the lattice. We show that our model quantitatively captures the experimental gap dynamics reported here of NbN and Nb3Sn through the picosecond timescale.

Comments

This article is published as Cui, Tianbai, Xu Yang, Chirag Vaswani, Jigang Wang, Rafael M. Fernandes, and Peter P. Orth. "Impact of damping on the superconducting gap dynamics induced by intense terahertz pulses." Physical Review B 100, no. 5 (2019): 054504. DOI: 10.1103/PhysRevB.100.054504. Posted with permission.

Copyright Owner

American Physical Society

Language

en

File Format

application/pdf

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