Closed-cycle microscopy cryostat

• Subject Area: Condensed Matter Physics
• Term: Funded in 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 538142921

We apply for a closed-cycle magneto-optical microscopy cryostat, having the following key characteristics. • Free-space optical access with cryo-compatible high-numerical-aperture microscope optics (NA > 0.8) . • Nanopositioning of the objective or the sample in three (xyz) degrees of freedom with better than 10 nm resolution and at least 5 mm range. • Microwave access for signals in the DC-20 GHz range. • Closed-cycle operation, independence from liquid Helium. • Base temperature below 6 Kelvin. • Variable sample temperature 6-300 K. • Vector control of the magnetic field with a magnitude of at least 5/1/1 T across entire temperature range. The combined instrument will enable my laboratory to perform microscopy and electron spin resonance spectroscopy on defect centers and organic molecules at cryogenic temperature, as well as cryogenic widefield magnetometry using ensembles of NV centers in diamond. We intend to employ this instrument for projects along three related scientific directions. • Single-molecule magnetic resonance: we will employ defect centers and microfabricated microwave resonators to detect and image nuclear and electron spins on the single-molecule level. • Study of defect centers and their light-matter interaction: we will investigate novel defect centers, as well as novel laser protocols to optically initialize and read their spin. • Widefield magnetometry: we will image magnetic fields at the microscale, using an ensemble of defect centers as an imaging sensor. Magnetic imaging will be employed in collaboration with other groups to image persistent currents in nanostructures and magnetism in 2D materials.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Trockenkryostat für Mikroskopie
• Instrumentation Group: 8520 Kryostaten, Tauchkühler (bis -100 Grd C)
• Applicant Institution: Universität Rostock
• Leader: Professor Dr. Friedemann Reinhard