Closed-Cycle Magnetic Cryostat with a tuneable open cavity for spectroscopy applications

• Subject Area: Condensed Matter Physics
• Term: Funded in 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 455536591

The new Closed-Cycle Cryostat, which combines highly spatially resolved free-space spectroscopy at sample temperatures between 4 K and 300 K and at magnetic fields reaching 9 T is the central equipment of this proposal. This cryostat will have an exposed role in the research activities of the Quantum Materials group at the University of Oldenburg. It will be essential for exploring the optical- and magneto-optical properties of novel quantum materials, TMDC monolayers and van-der-Waals heterostructures, as well as light-matter coupled hybrid systems. One of the central research activities of the group is the investigation of effects evolving in the regime of strong light-matter coupling between light- and matter in optical microcavities. In such coupled light-matter systems, exciton-polaritons evolve as hybrid excitations. The physics of polaritons is a research area of high contemporary relevance, as it has a direct application relevance (novel coherent light sources) and furthermore is of strong fundamental importance, e.g. in the investigation of collective excitations and phase transitions. In order to optimize and investigate quantum materials for their applications in cavity quantum electrodynamics experiments, a measurement system is required, which enables highly spatially resolved free space spectroscopy down to cryogenic temperatures. The cryostat needs to provide large magnetic fields, and the possibility to set up a so-called open cavity. It is in particular the latter, which demands a suppression of nearly all vibrations in the system. As a central piece of equipment of the quantum materials research group, it will open the door for a variety of collaborations within the university of Oldenburg and beyond.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Closed-Cycle Magnetkryostat für Spektroskopieanwendung
• Instrumentation Group: 8550 Spezielle Kryostaten (für tiefste Temperaturen)
• Applicant Institution: Carl von Ossietzky Universität Oldenburg
• Leader: Professor Dr. Christian Schneider