Project Details
Projekt
System for low-temperature magneto-optical spectroscopy
Subject Area
Condensed Matter Physics
Term
Funded in 2025
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 562331884
The requested equipment is intended for low-temperature magneto-optical spectroscopy of two-dimensional (2D) quantum materials, particularly 2D semiconductors and their heterostructures. The experimental focus is on fundamental research aimed at understanding the coupled optical, electronic, and magnetic properties of these materials using control parameters such as temperature and magnetic field. Understanding these materials serves as a potential foundation for future sensor technologies or applications in spintronics or (quantum) optoelectronics. Examples of materials of interest include the magnetically anisotropic semiconductor CrSBr, semiconducting transition metal dichalcogenides, and heterostructures of these materials for studying moiré and proximity effects, as well as new and largely unexplored 2D quantum materials, such as other transition metal chalcogen halides. In dual-gate heterostructures of these quantum materials, where electrostatic doping and the application of an electric field are possible via the field effect, various excitonic species (excitons – Coulomb-bound electron-hole pairs), as well as emergent quantum many-body states and their phase transitions, will be investigated using photoluminescence, photoluminescence excitation, and differential reflectance spectroscopy to shed light on their microscopic origins. Furthermore, these quantum materials will be embedded in optical microcavities to study the many-body states under strong light-matter interaction. The requested equipment, comprising a closed-cycle cryostat with a vector magnet and optical access, as well as accessories for nanopositioning, optical spectroscopy, and vacuum, a tunable titanium-sapphire laser, a supercontinuum laser, a spectrometer with charge-coupled device (CCD) camera, and wave plates, enables this measurement approach. The closed-cycle cryostat is required to measure excitons and polaritons (quasiparticles of strong light-matter interaction) at low temperatures (approximately 4 K) with significantly reduced thermal effects and to control the temperature. The vector magnet allows magnetic fields to be applied along different crystal axes, which is essential for magnetically anisotropic materials like CrSBr and for studying moiré magnetism to gain a comprehensive understanding of the magneto-optical properties of these materials. The tunable titanium-sapphire laser will be used as an excitation laser for photoluminescence and photoluminescence excitation spectroscopy across a wide spectral range. The supercontinuum laser serves as an intense white-light source for differential reflectance spectroscopy and as an excitation laser for photoluminescence. The spectrometer with a cooled CCD camera is used for spectrally resolved detection of the signals.
DFG Programme
Major Research Instrumentation
Major Instrumentation
System für die magneto-optische Tieftemperatur-Spektroskopie
Instrumentation Group
8550 Spezielle Kryostaten (für tiefste Temperaturen)
Applicant Institution
Technische Universität Braunschweig
