Tools for a nuclear demagnetization refrigerator 'on a chip'

在GaAs/AlGaAs中生长极高质量二维电子气（2DEG）的最新进展，其迁移率超过3000万cm^2/V.s，对应于接近毫米范围的弹性平均自由程，揭示了低温下各种新的分数量子霍尔（Fractional Quantum Hall）相，并对非阿贝尔量子统计进行了有趣的预测。特别是，最近发现了新的分数量子霍尔态，作为著名的5/2态的“卫星态”，被认为是从“高阶”非阿贝尔量子统计中出现的。为了使这些量子相发生，需要极低的温度，远低于20 mK。该建议涉及购买所需的设备和仪器，以构建一个核退磁制冷机“片上”，我们自己的设计，用于冷却电子远低于今天的最先进的特定目的。因此，我建议构建一个核退磁制冷机专门用于电子冷却，这将使我们的团队达到最冷的GaAs/AlGaAs电子温度。NSERC对这一提议的积极态度将使我们能够探索可能存在于最低温度下的全新奇异量子相。我们认为这是一个“奇妙的妙招”，对我们的学生和整个加拿大物理界非常有益，也是一个独特的机会，可以在竞争激烈的研究领域发挥世界领导者的作用。

Recent advances in the semiconductor growth of extremely high-quality two-dimensional electron gases (2DEGs) in GaAs/AlGaAs with mobility above 30+ million cm^2/V.s, corresponding to an elastic mean free path approaching the millimeter range, have unraveled a variety of new Fractional Quantum Hall (FQH) phases at low temperatures with interesting predictions of non-abelian quantum statistics. In particular, new fractional quantum Hall states were discovered recently as 'satellite states' of the well-celebrated 5/2 state that are thought to occur from 'higher-order' non-abelian quantum statistics. For these quantum phases to occur, extremely low temperatures are required, well below 20 mK. This proposal concerns the purchasing of equipments and instrumentations required to construct a nuclear demagnetization refrigerator 'on-chip', of our own design, for the specific purpose of cooling electrons well below today's state-of-the-art. I therefore propose to construct a nuclear demagnetization refrigerator specifically for electron cooling which will allow our group to reach the coldest GaAs/AlGaAs electronic temperature ever. A positive take on this proposal by NSERC will allow us to explore totally new exotic quantum phases that may exist at the lowest temperatures. We view this as a 'fantastic coup', highly-beneficial for our students and the overall Canadian physics community, as well as a unique opportunity to take the role of a World leader in an extremely competitive field of research.