Ultrafast Magnetometry of (Light-Induced) Superconductors

G. Jotzu,1,2 S. Fava,2 M. Buzzi,2 G. De Vecchi,2 A. Cavalleri2

1Dynamic Quantum Materials Laboratory, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland

2Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany

Driving certain cuprates and organic materials has been shown to induce THz optical properties reminiscent of superconductivity far above the equilibrium transition temperature. However, the magnetic response of these non-equilibrium states remains unexplored. This study investigates whether these states exhibit a Meissner effect, expelling external magnetic fields, and examines their response to changing magnetic fields on sub-picosecond time scales.

Our methodology involves studying the ultrafast magnetic response of these materials in static and time-dependent magnetic fields using the Faraday effect in a magneto-optical crystal adjacent to the sample. This provides sub-picosecond time resolution for reconstructing the position-dependent magnetic properties.

Beginning with the investigation of the destruction of superconductivity below Tc, we explore signs of the light-induced appearance of superconductivity far above Tc. Our study examines the temperature and magnetic field dependence of these phenomena, offering new insights into the non-equilibrium dynamics of these systems.

Furthermore, we discuss how this method could be extended to probe the dynamics of other laser-driven strongly correlated materials. This research sheds light on the unique properties of non-equilibrium states and their potential applications in the field of condensed matter physics.