Grant: Research Tools and Instruments - Category 1 (<$150,000)

This proposal is for the purchase of a closed-cycle low temperature cryostat for high-resolution electronic structure studies on novel quantum materials and structures. This effort combines the Quantum Materials Lab of Damascelli with the Femtosecond Frequency Combs Lab of Jones, which together have developed at UBC world-class infrastructure for laser-based angle-resolved photoemission spectroscopy (ARPES). This facility has already provided major breakthroughs in the study of high-Tc superconductors, topological insulators, and in carbon-based materials with the first ever demonstration of superconductivity in single-layer graphene. Quantum mechanical phenomena in solids are smeared out when the temperature rises above 4 degrees Kelvin, requiring extensive experimental work at liquid He temperatures. Damascelli and Jones must cool their measurement equipment down to about 4K, and for this they have so far used liquid He flow cryostats, as opposed to close-cycle systems that typically generate vibrations incompatible with the sensitive measurements to be performed. Unfortunately, with continuous flow systems liquid He rapidly boils away and is lost to the atmosphere. At present, the ARPES effort as a whole is spending approximately $100,000/year to consume one of the earth's most precious and non-renewable resources, releasing it into the atmosphere to escape into space. This is both extremely costly and not environmentally viable. This RTI proposal takes advantage of a new closed-cycle cryostat manufactured by ColdEdge Technologies: a proprietary ultra-low vibration He-gas-based interface dramatically reduces vibrations to the level required for laser-ARPES, and potentially even for Scanning Tunneling Microscopy (STM). This closed-cycle cryostat will be retrofitted into the current ARPES infrastructure, and will also be used by collaborators Bonn and Burke from the Superconductivity and STM labs to evaluate the possibility of incorporating such system into an STM apparatus. The ability to remain indefinitely at very low temperature - with zero He consumption - will break new ground into what experiments may be possible in highly advanced electron spectroscopies.