Regensburg 2019 – wissenschaftliches Programm
TT 57.5: Vortrag
Donnerstag, 4. April 2019, 16:00–16:15, H7
Optical second-harmonic generation spectroscopy of superconducting YBa2Cu3Oy — •M.C. Weber1, Th. Lottermoser1, T. Loew2, J.P. Porras2, D. Hsieh3, B. Keimer2, and M. Fiebig1 — 1Department of Materials, ETH Zurich — 2Max-Planck Institute, Stuttgart — 3California Institute of Technology, Pasadena
The cuprate-family – famous for their high-Tc superconductivity – is characterized by a complex phase diagram. The understanding of competition or coexistence of the different phases represents one of the intriguing questions in the field. An important milestone in order to scrutinize these questions is the understanding of the symmetry properties of the different phases. Recently, using optical second-harmonic generation (SHG) a new study on YBa2Cu3Oy revealed a monoclinic symmetry at RT followed by an inversion-symmetry breaking upon entering the pseudo-gap phase . The introduction of this symmetry-sensitive technique into the realm of superconductivity opens new doors for the investigation of the rich phase diagram of YBa2Cu3Oy-compounds. In particular, spectroscopic SHG-studies allow for a deeper insight into the microscopic nature and electronic origin of the optical nonlinearities. In the present work, we report a thorough SHG-spectroscopy investigation on YBa2Cu3Oy-compounds. We find a strong spectral dependence of the optical non-linear response. Tracing the evolution of this spectral dependence across phase transitions, we aim to enlarge the understanding of the complex phase diagram of the cuprate-family.
 Zhao et al., Nat. Phys. 13, 250 (2017)