Intellectual Merit -- The goal of this project is to acquire and set up a cryogen-free dilution refrigerator with a base temperature of about 0.010 Kelvin and a superconducting magnet with a maximum field of 12 Tesla. This equipment will be shared by eight Principal Investigators and collaborators, and will be used by their graduate and undergraduate students, post-docs and research staff. It will be initially devoted to measurements of electronic properties of low-dimensional semiconductor structures, topological insulators, and graphene. All these material systems are at the forefront of current, fundamental solid state physics and device research. They also have potential transformative applications, e.g., in quantum computing and information processing. The cryogen-free system will enhance the research on these materials in several crucial ways: (1) It will allow measurements at low temperatures and in tilted magnetic fields to learn exciting new physics. (2) Because the operation of the proposed equipment is much simpler than the conventional dilution refrigerators, it will tremendously enhance the efficiency of the measurements and research progress. (3) It will allow the inclusion of undergraduate students in research projects more easily. (4) It will replace our existing equipment which is instrumental to our research but is over 20 years old, has frequent problems, and does not reach below about 0.03 Kelvin. (5) Each year it will save over $100,000 worth of materials (liquid Helium) cost. This will have a huge impact on the ability to make measurements and produce new results more efficiently. (6) It will save Helium, a precious noble gas. Broader Impacts -- The impact of the proposed project will be seen in the scientific community and beyond. Results of the research will be communicated through publications and conference presentations to the specialized as well as general science and engineering communities. While the subject of this project is fundamental, progress in this area will benefit society in the long term as it may lead to novel, transformative concepts for electronic materials and devices and information processing systems whose operation relies on quantum and/or interaction phenomena. The project incorporates a high quality and comprehensive educational component. The PIs are dedicated to the education of both graduate and undergraduate students. They all have typically small groups (4 to 6) of students, and their belief is that doing good quality research, with close supervision, is the best way to teach beyond textbooks and problem sets. The project will therefore result in the education of students in critical, state-of-the art areas of science and technology, including the fabrication, characterization, and physics of high quality layered semiconductor structures and other novel materials such as topological insulators and graphene. Well-trained students in these fields will be invaluable resources for the US as well as for the rest of the world. The PIs will also make every effort to attract to this project students from underrepresented groups. The PIs are committed to a broader education of the public in science and engineering. Some of the topics and results of this project will be incorporated into undergraduate and graduate courses that they teach at Princeton University. The PIs will also participate in various K-12 demonstrations and teacher training programs in electricity and magnetism and in cryogenic temperatures, general areas that are closely linked to the topic of this proposal. These activities include training sessions, kit development, and demonstrations at regional schools and at Princeton University.
