EAGER: CRYO: Development of materials and techniques to enable sub-Kelvin cooling via adiabatic decompression of para-nematic materials.

斯坦福大学的研究人员开发了一种新方法，可以将材料冷却到绝对零度以内，而不需要使用昂贵的液氦。这种极端温度对于各种现代技术来说都是必要的，包括量子计算机的一些实现。这个高风险/高回报的项目由化学、生物工程、环境和运输系统部门以及材料研究部门共同支持，研究一种交替挤压材料然后释放压力的方法。虽然操作原理很简单，但该技术需要发现具有非常特定物理性质的适当材料。拟议的研究将确定和表征这些材料，以实现更可持续的超低温冷却方法。斯坦福大学的研究人员研究了一种达到亚开尔文温度的新方法。该方法的工作原理是交替挤压材料，然后释放应变，通过绝热减压的过程中提到的奖项名称。对于功能材料，考虑了一类特定的含稀土化合物，其诱导应变的适度变化可能导致较大的温度变化，即准向列材料。与现有技术相比，研究人员使用这种材料进行低温冷却的方法有几个特殊的优势：它不需要氦-3，不需要磁场，而且可以快速循环。该项目由化学、生物工程、环境和运输系统司和材料研究司联合支持，有三个主要目标：开发适当的候选材料；改进了其热弹性性能的低t表征；然后还原成热力学循环。要进行的活动包括晶体生长和候选材料的表征；在大应变范围内测量低温弹热响应；测温技术的改进；设计，建造和测试一个简单的工作模型来证明这种冷却效果。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Part 1: Non-Technical SummaryResearchers at Stanford University develop a new method to cool materials to within a degree of absolute zero without requiring the use of costly liquid helium. Such extreme temperatures are necessary for a variety of modern technologies, including some realizations of quantum computers. This high risk/high reward project, which is jointly supported by the Division of Chemical, Bioengineering, Environmental and Transport Systems and the Division of Materials Research, investigates an approach that works by alternately squeezing materials and then releasing the strain. While the operating principle is straight forward, the technique requires discovery of appropriate materials with very specific physical properties. The proposed research will identify and characterize such materials to enable a more sustainable approach to ultra-low temperature cooling. Part 2: Technical SummaryResearchers at Stanford University investigate a new approach to reaching sub-Kelvin temperatures. The method works by alternately squeezing materials and then releasing the strain, through the process of adiabatic decompression referred to in the award title. For the functional material, a specific class of rare earth containing compounds are considered, for which large temperature changes are possible for modest changes in induced strain, i.e. para-nematic materials. The researchers’ approach to use such materials for cryogenic cooling has several specific advantages over existing technologies: it does not require He-3, it does not require magnetic fields, and it can be rapidly cycled. The project, which is jointly supported by the Division of Chemical, Bioengineering, Environmental and Transport Systems and the Division of Materials Research, has three main objectives: development of appropriate candidate materials; improvement in low-T characterization of their thermo-elastic properties; and reduction to a working thermodynamic cycle. Activities to be performed include crystal growth and characterization of candidate materials; measurement of low-temperature elastocaloric response over a wide range of strains; improvements in thermometry; and design, construction and testing of a simple working model that would demonstrate such a cooling effect.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.