Cavity-controlled magnetic excitons in van der Waals magnets

• Applicant: Dr. Florian Dirnberger
• Subject Area: Experimental Condensed Matter Physics
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 534078167

Strong coupling of light and matter can significantly impact the properties of solid-state systems. Recently, a new type of optical matter excitation was found in magnetic van der Waals materials. Spectroscopy studies of these excitations termed magnetic excitons relate their pronounced interaction with magnetism directly to spin-polarized electronic states with long-range magnetic order and to magnons. My recent work demonstrates the strong coupling of these anomalous excitons to cavity photons and introduces the resulting magnetic exciton-polaritons as a valuable platform for strong light-matter physics. In this project, I propose to implement and investigate this new class of polaritons in different van der Waals magnetic systems and optical cavities to advance the field of magneto-optics. Because of the presence of strong coupling, established methods of ultrafast polariton spectroscopy emerge as a viable experimental tool for the study of non-equilibrium dynamics and critical phenomena at magnetic phase transitions. Moreover, innovative concepts such as polariton memory, combining multi-bit storage with ultrasensitive optical read-out, or magnetic polariton lasers, which may result from polariton condensation, can now be realized in van der Waals magnets embedded in microcavities.

• DFG Programme: Independent Junior Research Groups
• Major Instrumentation: Cryostat with high field manet and optical access ; Pulsed laser source ; Spectrometer & CCD
• Instrumentation Group: 1800 Spektralphotometer (UV, VIS), Spektrographen (außer Monochromatoren 565) ; 5700 Festkörper-Laser ; 8550 Spezielle Kryostaten (für tiefste Temperaturen)