Damjan Pelc
School of Physics and Astronomy, University of Minnesota, Minneapolis, USA
Nonlinear response in superconductors
mjesto: FO, F-201
vrijeme: petak 13. 7. 2018 u 14:15
Nonlinear response to low-frequency electromagnetic fields is an experimental technique that is rarely used to study superconductors.
However, it is capable of providing a wealth of information beyond what is possible with the standard linear response measurements. I will discuss two distinct classes of nonlinear response, their symmetry properties, and how they can be employed to study unconventional superconductors. The experimental approach enables new insights into the physics of some of the most explored materials: I will show how nonlinear susceptibility can be used to detect chiral edge currents in candidate triplet superconductors, and demonstrate the sensitivity of nonlinear response to superconducting fluctuations above the macroscopic transition temperature. The latter is used to reveal a surprising universal precursor regime in different perovskite-based superconductors, including the high-Tc cuprates. Finally, I will discuss possible extensions and future directions for nonlinear response measurements in complex materials.