Berlin 2015 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 85: Superconductivity: Higgs Modes in Condensed Matter and Quantum Gases (jointly with DY, MA, O)
TT 85.2: Vortrag
Donnerstag, 19. März 2015, 10:00–10:15, H 2053
Nonadiabatic dynamics and coherent control of nonequilibrium superconductors — •Andreas Schnyder1, Holger Krull2, Dirk Manske1, and Götz Uhrig2 — 1Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany — 2Lehrstuhl für Theoretische Physik I, Technische Univerität Dortmund, Otto-Hahn Straße 4, 44221 Dortmund, Germany
Inspired by recent THz pump-THz probe experiments on NbN films [1], we theoretically study the pump-probe response of nonequilibrium superconductors coupled to optical phonons. For ultrashort pump pulses a nonadiabatic regime emerges, which is characterized by amplitude oscillations of the superconducting gap [2] and by the generation of coherent phonons [3]. Using density-matrix theory as well as analytical methods, we compute the pump-probe response of the superconductor in the nonadiabatic regime and determine the signatures of the order parameter and of the phonon oscillations in the pump-probe conductivity. We find that the nonadiabatic dynamics of the superconductor reflects itself in oscillations of the pump-probe response as a function of delay time between pump and probe pulses [4]. We also consider two-band superconductors and study the interplay of the two amplitude oscillations of the two gaps.
[1] R. Matsunaga et al., PRL 111, 057002 (2013)
[2] E. A. Yuzbashyan et al., PRL 96, 097005 (2006)
[3] A. P. Schnyder, D. Manske, and A. Avella, PRB 84, 214513 (2011)
[4] H. Krull, D. Manske, G. S. Uhrig, and A. P. Schnyder, PRB 90, 014515 (2014)