EAGER: CRYO: Refrigeration across temperature scales with electrically-tunable spin-orbit materials

EAGER：CRYO：利用电可调自旋轨道材料实现跨温标制冷

• 批准号: 2233111
• 负责人: Ravishankar Sundararaman
• 金额: $ 29.72万
• 依托单位: Rensselaer Polytechnic Institute
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2233111&HistoricalAwards=false
• 关键词: EAGER; CRYO; Refrigeration; across; temperature

Non-technical summaryQuantum computing and communication technologies, which will become increasingly critical for competitiveness and security in the next phase of the information age, require ultralow temperatures that are hundreds to thousands of times smaller than room temperature. Currently the predominant approach to reach such temperatures relies on repeatedly mixing and separating two isotopes of helium, He-3 and He-4, in a dilution refrigerator. However, helium in general, and He-3 in particular, are rare and increasingly expensive. This poses a severe challenge to the widespread adoption of quantum technologies. With this high risk/high reward project, supported by the Division of Materials Research, researchers at the Rensselaer Polytechnic Institute investigate a new approach for achieving ultralow temperatures without relying on rare elements. Specifically, they leverage the unique interactions of the spin of electrons in a class of materials called Rashba materials with electric fields. Preliminary simulations show that switching a voltage applied to these materials on and off in a specific pattern and direction may allow reaching low temperatures efficiently, making these potentially promising materials to compete with dilution refrigerators. In addition to enabling the widespread adoption of quantum technologies, the success of this new approach to reach very low temperatures could make a wide range of low-temperature phenomena, such as superconductors, more scientifically and technologically accessible. To educate the next generation of STEM workforce, the researchers integrate the underlying theory and experimental demonstrations of ultralow temperature refrigeration into undergraduate and graduate curricula as well as high-school outreach programs. This helps introduce future scientists and engineers to the technological challenges on the path to the age of quantum information.Technical summaryWith support from the Division of Materials Research, the researchers leverage Rashba spin-orbit coupling in materials as a new platform for enabling new approaches to reach ultralow temperatures down to 0.01 K, breaking the current dependency on the extremely rare He-3 isotope required by dilution refrigerators. They study new thermodynamic cycles that take advantage of the dependence of the electronic entropy on electric fields, due to the change of the spin-orbit splitting with electric field strength in Rashba materials. In particular, they investigate the possibility for refrigeration by adiabatic electrification of Rashba materials and determine if this can provide sufficient cooling power that matches or even exceeds that of typical dilution refrigerators. Research objectives include exploring a wide class of Rashba materials with different spin-orbit coupling strengths, synthesize structures capable of electric field cycling in these materials and quantify the field- and temperature-dependent thermodynamic parameters of these materials relevant for refrigeration. If successful, this approach may be extensible to a wide temperature range due to the broad range of Rashba energy splits, potentially opening up a pathway to cool from liquid nitrogen to millikelvin temperatures in a single material platform.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术摘要计算和通信技术将对信息时代的下一个阶段对竞争力和安全至关重要，需要超高温度比室温小数百至千倍。目前，达到此类温度的主要方法依赖于在稀释冰箱中反复混合和分离两个氦同位素He-3和He-4。但是，通常，氦气，特别是HE-3，很少见，而且越来越昂贵。这对量子技术的广泛采用构成了巨大挑战。借助材料研究部门的支持，伦斯勒理工学院的研究人员研究了一种新的方法来实现超高温度，而不依赖稀有元素，则研究了一种新方法。具体而言，它们利用电子自旋在一类称为Rashba材料与电场的材料中的独特相互作用。初步模拟表明，以特定的模式和方向开关向这些材料施加电压可能可以有效地达到低温，从而使这些潜在的有希望的材料与稀释冰箱竞争。除了能够广泛地采用量子技术外，这种新方法达到非常低的温度的成功还可以使广泛的低温现象（例如超导体，更科学和技术上可以访问）。为了教育下一代STEM劳动力，研究人员将超低温度制冷的基本理论和实验演示整合到本科和研究生课程中，以及高中课程。这有助于向未来的科学家和工程师介绍量子信息时代的技术挑战。技术摘要与材料研究部的支持，研究人员在材料中利用Rashba Spin-Orbit耦合材料作为新的平台，作为一种新方法，使新的方法使超过0.01 k的超值温度降低至0.01 K，破坏了当前的依赖依赖于HE-3 IS-3 IS-3 IS-3。他们研究了新的热力学循环，这些循环利用了电子熵对电场的依赖性，这是由于旋转轨道分裂在Rashba材料中使用电场强度的变化。特别是，他们研究了通过绝热的RashBA材料电气化来制冷的可能性，并确定这是否可以提供足够的冷却能力，使匹配甚至超过典型稀释冰箱的冷却能力。研究目标包括探索具有不同自旋轨道耦合强度的各种RASHBA材料，合成能够在这些材料中循环的电场循环的结构，并量化这些材料的田间和温度依赖性的热力学参数，这些材料与制冷有关。如果成功的话，由于Rashba能量分裂的广泛范围，这种方法可能可以扩展到广泛的温度范围，从液氮到单个材料平台中的Millikelvin温度，有可能打开一种途径，该奖项反映了NSF的法定任务，并通过使用该基金会的知识优点和广泛的范围来评估NSF的法定任务，并通过评估有价值。