Collapse of high-Tc superconductivity via ultrafast quenching of the phase coherence

Condensed Matter Seminars

Speaker: Fabio Boschini, SBQMI, UBC
Date & Time: Thu, 2017-10-19 14:00 - 15:00
Location: AMPEL #311
Local Contact: Andrea Damascelli
Intended Audience: Graduate

One of the most fascinating properties of low-density condensates is the emergence of phase transitions driven solely by the fragility of the phase coherence. This intriguing physics has triggered an intense search for tools to control the rigidity of superconducting phases and investigate the collapse of superconductivity induced by phase fluctuations. Electrically-gated oxide interfaces, ultracold Fermi atoms and cuprate superconductors, which are characterized by an intrinsically small phase-stiffness, are paradigmatic examples. Here, we use ultrashort light pulses to probe and drive the phase fragility of the Bi2Sr2CaCu2O8+δ cuprate superconductor, up to the point of completely quenching the phase coherence without affecting the electron pairing. Time-resolved photoemission is used to track and disentangle the dynamics of phase fluctuations and charge excitations. This work demonstrates the dominant role of phase coherence in the emergence of high-temperature superconductivity and offers a new benchmark for non-equilibrium investigations of the phase diagram.