Repair of Helium-3 Refrigerator for Cryomagnetic Nanoprobe Experiments

这项RTI提案要求资金来修复现有的氦-3冰箱，这对于继续PI的大部分研究计划和研究生培训是必不可少的，这两项都是由发现基金资助的。这台冰箱已经投入生产运行了十多年，但今年早些时候，由于低温老化，它发生了灾难性的故障，导致它失去了所有的氦-3，而氦-3是超低温冷却所需的主要物质。修复将包括重建冰箱，用氦-3重新充电，并使其恢复到新的低温操作状态。这种专用的冰箱用于在复杂的氧化物和金属间材料上进行低温磁性纳米探针实验（低至300开尔文，高至9特斯拉），这些材料既具有非常规的超导性，又具有拓扑现象。科学的目标是检查这些量子材料现象的基本特征，朝着阐明潜在的物理机制。技术目标是利用这些现象用于纳米电子器件，如超高速晶体管和量子器件，如拓扑计算元件。除了科学知识的进步，这些实验中涉及的低温磁和纳米探针技术是当今凝聚态物理、材料科学和纳米工程领域最尖端的技术之一，对加拿大具有深远的技术效益。

This RTI proposal requests the funding to repair an existing helium-3 refrigerator, which is indispensible for continuing the bulk of the PI's research program and graduate student training, both funded by the Discovery Grant. The refrigerator has been in productive operation for over a decade, but earlier this year it broke down catastrophically due to cryogenic aging, causing it to lose all of its helium-3 which is the main substance needed for the ultralow temperature cooling. The repair will involve rebuilding the refrigerator, recharging it with helium-3 and reviving it for as-new cryogenic operation. This specialized refrigerator is used to carry out cryomagnetic nanoprobe experiments (down to 300 milliKelvin and up to 9 Tesla) on complex oxide and intermetallic materials that exhibit both unconventional superconductivity and topological phenomena. The scientific goal is to examine the essential characteristics of these quantum materials phenomena, towards elucidating the underlying physical mechanisms. The technological goal is to harness these phenomena for use in nanoelectronic devices such as ultra high-speed transistors and in quantum devices such as topological computing elements. In addition to the advancement of scientific knowledge, the cryomagnetic and nanoprobe techniques involved in these experiments are among the most cutting-edge in condensed matter physics, materials science and nanoengineering today, with far-reaching technological benefits for Canada.