Magneto optic cryostat and Raman spectrometer for equilibrium and time domain experiments

• Subject Area: Condensed Matter Physics
• Term: Funded in 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 525701273

The possibility of obtaining new material functionalities in the strong light-matter coupling regimes has been demonstrated across different scientific disciplines. The effort of using the strong coupling concepts to obtain new material functionalities in complex quantum materials has been somewhat smaller and mostly limited to theoretical proposals. Different theoretical proposals indicate that THz cavities can manipulate the superconducting order-parameter phase coherence by coupling the optical cavity mode to Josephson plasma resonances or to high energy electronic excitations to induce long-range attractive interaction between electrons. The research goal of the research unit which we will establish through this proposal aims at understanding the equilibrium and non-equilibrium optical properties of complex materials embedded in cryogenic optical cavities in magnetic field. In particular, we propose here the implementation of a magneto optic cryogenic platform to perform high resolution Raman spectroscopy/thermometry of light matter assembly on samples in cryogenic optical cavities and strong magnetic field. In detail we will develop a lab capable of measuring the dependence on the magnetic field of the Raman Stokes and anti-Stokes scattering (static and time dependent) of complex materials embedded into Fabri-Perot optical cavity. The Raman thermometry provide the key to measure in situ the temperature of a sample embedded into the cavity without perturbing the resonance condition. This is crucial to study the thermodynamic of light-matter hybrid phases. Additionally, the setup proposed enables research programs focused on the simultaneous perturbation of sample’s environment through an intense magnetic field and tuneable optical cavity. An example to highlight the scientific case comes from the physics of inhomogenous superconductor where a strong magnetic field inhibits the formation of a macroscopic superconducting state, while according to some theoretical prediction the presence of a stationary state and driven cavity can favour the onset of macroscopic condensate. We will study if, and eventually how, the appropriate tuning of the optical cavity combined with resonant photoexcitation with mid-IR pulses, can contrast the quench of the superconducting order parameter driven by the magnetic field.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Magneto optic cryostat and Raman spectrometer for equilibrium and time domain experiments
• Instrumentation Group: 1840 Raman-Spektrometer
• Applicant Institution: Friedrich-Alexander-Universität Erlangen-Nürnberg
• Leader: Professor Dr. Daniele Fausti