Can I read Twisting Anderson pseudospins with light: Quench dynamics in THz-pumped BCS superconductors on EtoBox?

Twisting Anderson pseudospins with light: Quench dynamics in THz-pumped BCS superconductors by Chou, Yang-Zhi; Liao, Yunxiang; Foster, Matthew S. is a scholarly article available to read on EtoBox.

What is Twisting Anderson pseudospins with light: Quench dynamics in THz-pumped BCS superconductors about?

We study the preparation (pump) and the detection (probe) of far-from-equilibrium BCS superconductor dynamics in THz pump-probe experiments. In a recent experiment [R. Matsunaga, Y. I. Hamada, K. Makise, Y. Uzawa, H. Terai, Z. Wang, and R. Shimano, Phys. Rev. Lett. {\bf 111}, 057002 (2013)], an intense monocycle THz pulse with center frequency $\omega \simeq \Delta$ was injected into a superconductor with BCS gap $\Delta$; the subsequent post-pump evolution was detected via the optical conductivity. It was argued that nonlinear coupling of the pump to the Anderson pseudospins of the superconductor induces coherent dynamics of the Higgs (amplitude) mode $\Delta(t)$. We validate this picture in a two-dimensional BCS model with a combination of exact numerics and the Lax reduction method, and we compute the nonequilibrium phase diagram as a function of the pump intensity. The main effect of the pump is to scramble the orientations of Anderson pseudospins along the Fermi surface by twisting them in the $xy$-plane. We show that more intense pump pulses can induce a far-from-equilibrium phase of gapless superconductivity ("phase I"), originally predicted in the context of interaction que

Author

Chou, Yang-Zhi; Liao, Yunxiang; Foster, Matthew S.

Published

2016

Language

EN