Low-temperature quantum measurement system with vector magnet

• Subject Area: Condensed Matter Physics
• Term: Funded in 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 556173910

The main objective of this project is the investigation of quantum effects to further develop quantum technologies in the field of solid-state based quantum devices. As basic building blocks we consider superconducting quantum circuits operated at cryogenic temperatures in the milli-Kelvin range. We specifically aim to investigate the physical origin of noise sources in superconducting quantum circuits to improve their coherence properties, and to explore scalable control techniques to overcome the limits of current controllability. Moreover, we plan to investigate hybrid semi-superconductor quantum systems for the coherent transfer of quantum states between distant systems. To successfully carry out these research projects, we plan to install and operate a dilution refrigerator. In addition to standard microwave control electronics the instrument includes a fibre-based optical access for controlling qubits and for transducing quantum signals between the microwave and the optical frequency range using quantum dot molecules. For the control of such hybrid devices and for the investigation into the origin of decoherence we plan to include a vector magnet to apply well-controlled magnetic bias fields. The setup is completed with microwave control electronics to characterize, control and readout the state of the quantum systems. A vector network analyser is used to efficiently measure the microwave response of the system to characterize its quantum and classical properties. A qubit controller is used to synthesize arbitrary waveforms at the relevant transition frequencies and to directly measure the qubit states. The proposed setup ensures versatility for a large range of parameters and experiments. It is therefore ideally suited to explore the physics of complex quantum systems and to provide a path towards technological applications.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Tieftemperatur-Quantenmesssystem mit Vektormagnet
• Instrumentation Group: 8550 Spezielle Kryostaten (für tiefste Temperaturen)
• Applicant Institution: Technische Universität München (TUM)
• Leader: Professor Dr. Stefan Filipp