Two cryogen-free dilution refrigerators

EPFL wishes to acquire two cryogen-free dilution refrigerators for advanced low-temperature research. Both systems must allow operation in the millikelvin regime and be equipped with superconducting magnets. The first system must be a large-capacity cryogen-free dilution refrigerator, equipped with a superconducting vector magnet providing nominal fields of at least 6 T along the main axis and 1 T along each of the two transverse axes. This system must also include a bottom-loading system, or an equivalent rapid sample exchange system, allowing sample replacement without warming up the entire cryostat and allowing the cooling of the loaded sample holder to a temperature below 20 mK in less than 8 hours. The second system must be a smaller cryogen-free dilution refrigerator, equipped with a single-axis superconducting solenoid magnet providing a nominal field of at least 8 T. This system must allow for rapid experimental turnaround, with a cooling time from ambient temperature to base temperature of approximately 12 hours or less without the magnet installed. The supplier must specify the cooling time with the magnet installed. The equipment will support cutting-edge research on quantum magnetic materials, superconducting quantum circuits, semiconductor quantum devices, and hybrid microwave/semiconductor quantum technologies. Given EPFL's needs and the specific scientific objectives of the LQM, HQC, and LQP laboratories, particular attention will be paid to the following research areas: • Correlated electron materials, ranging from local spin clusters to novel superconductors • Semiconductor quantum systems at millikelvin temperatures and high magnetic fields • Superconducting quantum circuits at microwave frequencies • Hybrid semiconductor-superconductor quantum devices • Quantum materials and devices based on III-V and group IV semiconductor heterostructures, superconducting metals, and Josephson junctions