Seminars Archive

Laser induced phase transitions in superconductors

Abstract
I am going to present the study of the phase transitions by three-pulse technique in cuprate superconductors as well as new results on laser induced switching between resistive states in superconducting nanowires. I report the study of the normal-to-superconducting transition in LSCO for a set of destruction fluences covering different regimes of the transition. The experimental results are compared with a set of numerical solutions of time-dependent Ginzburg-Landau theory formulated with different key assumptions. Reliable agreement with experiment is achieved when thermal fluctuations are suggested to play a dominant role in seeding the order parameter. Additionally I will present the results of the three-pulse experiments in BSCCO system, and compare general trends in the pseudogap and the superconducting phases. In the final part of the presentation I will report recent observation of the laser induced switching between the dynamical superconducting current-carrying states called phase-slip centers, observed in nanowires of conventional superconductor δ-MoN. The experiments show the possibility of switching between not only known states but also accessibility of short- and long-lived hidden states.