Transient Dynamics of d-Wave Superconductors after a Sudden Excitation

MPSD Seminar

Date: May 3, 2016
Time: 04:00 PM - 05:00 PM (Local Time Germany)
Speaker: Francesco Peronaci
International School for Advanced Studies (SISSA), Trieste, Italy
Location: CFEL (Bldg. 99)
Room: Seminar Room IV, O1.111
Host: Martin Eckstein

In this talk I will discuss the transient dynamics of a d-wave BCS model after a quantum quench of the interaction parameter. The motivation comes from recent ultrafast pump-probe experiments on high-temperature superconductors.

It is found that the existence of gap nodes, with the associated nodal quasiparticles, introduces a decay channel which makes the dynamics much faster than in the conventional s-wave model. For every value of the quench parameter, the superconducting gap rapidly converges to a stationary value smaller than the one at equilibrium. Using a sudden approximation for the gap dynamics, one finds an analytical expression for the reduction of spectral weight close to the nodes, in qualitative agreement with the experimental results.

References:

[1] F. Peronaci, M. Schiró and M. Capone, Phys. Rev. Lett. 115, 257001 (2015).

[2] J. Graf, C. Jozwiak, C. L. Smallwood, H. Eisaki, R. A. Kaindl, D-H. Lee, and A. Lanzara, Nature Physics 7, 805–809 (2011).