Search for new phases of the exotic superfluid 3He under nanoconfinement

在纳米限制下寻找奇异超流体 3He 的新相

• 批准号: 2002692
• 负责人: Jeevak Parpia
• 金额: $ 49万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2002692&HistoricalAwards=false
• 关键词: Search; new; phases; exotic; superfluid; Search; new; phases; exotic; superfluid

Non-technical AbstractMost consumer items utilize technology that emerged because of advances in condensed matter research. Future advances will be enabled by the sort of “curiosity driven” exploration of new regimes accessible only in a laboratory environment. The research to be conducted in this program will examine the special properties of superfluid 3He when confined in precisely defined structures less than a thousandth of a millimeter tall, marking the transition from bulk so-called 3 dimensional behavior to a new 2 dimensional regime. Undergraduate students and a Ph.D student will build on cutting edge knowledge to design and fabricate these structures opening up a new area of quantum nano-fluidics. The surfaces will have to have a well-defined smoothness since the smoothness (alterable with a coating of helium 4) changes the scattering at the surface much like a mirrored surface is different from a frosted surface. This scattering quality (together with the confinement) can also change the types of superfluid states (“phases”) that emerge. These phases should show a property “chirality” that should have properties like a spinning top. These new phases should exhibit novel characteristics such as highly conducting “edge states” that are scientifically “exciting” and that could, in the future form the basis of new types of devices for metrology and computation. Past graduate students and undergraduates of this team have gone on to productive careers in academia, high-technology industries and the financial sector, and the planned research will prepare a new generation of students for challenging careers. Technical abstract:Superfluid 3He can inform research activity that extends across many fields in Physics. The project combines nanofluidics (intricate and precisely fabricated silicon cavities with sizes tuned to the scale of the superfluid’s coherence length) with low temperature physics, to expose new size effects. The experimental activity will probe excitations using transport (superfluid density and heat conductivity) as well as novel noise thermometry and a nanowire to act as local thermometers. Researchers expect that entirely new p-wave superfluid states can be stabilized by such confinement and the balance between the superfluid ground state that preserves (3He-B) or breaks (3He-A) time reversal symmetry will also be affected by confinement. By measuring the phase diagram of confined 3He, details of the pressure and temperature dependence of the strong coupling strength will be mapped out allowing for more reliable prediction of the phase diagrams of 3He under confinement. Confinement will also provide the means to study the surface/edge excitations emerging as a result of bulk/edge correspondence. Studies of the hysteresis in the first-order transition between the confined A and B phases (radically different from nucleation in bulk) will challenge current understanding of these quantum transitions. New geometries will explore the physics of quantum transport across single and multiple interfaces. By combining low temperatures and nano fabrication, graduate students and undergraduates will be exposed to the exciting training ground that has prepared scientists for lead roles in academia and high-technology industries. Eventually, the new superfluids that emerge under confinement might be of interest in quantum computation.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.

非技术抽象的最多消费者项目利用由于凝结物质研究的进步而出现的技术。仅在实验室环境中可以访问的新政权的“好奇心驱动器”探索将实现未来的进步。当该计划中进行的研究将检查超过3毫米的精确定义结构的特殊特性，而小于千分之一毫米的高度，这标志着从所谓的3维行为到新的2维度方案的过渡。本科生和博士学位的学生将基于最先进的知识，以设计和制造这些结构开辟了新的量子纳米流体学领域。表面将必须具有明确定义的平滑度，因为平滑度（可改变氦气4的涂层4）会改变表面的散射，就像镜面表面一样，与磨砂表面不同。这种散射质量（以及限制）也可以改变出现的超流体状态（“相位”）的类型。这些阶段应显示一个特性“手性”，该特性应该具有像旋转顶部一样的属性。这些新阶段应该表现出新颖的特征，例如高度执行“边缘状态”，这些特征在科学上是“令人兴奋的”，并且在将来可能构成了新型计量和计算设备的基础。该团队的过去研究生和本科生一直从事学术界，高科技行业和金融领域的产品职业，计划的研究将为新一代学生做好挑战职业的准备。技术摘要：Superfluid 3HE可以为研究活动提供信息，这些研究活动扩展了许多物理领域的领域。该项目结合了纳米流体（复杂和精确制造的硅腔，尺寸调整为超级流体相干长度的尺度）和低温物理学，以暴露新的尺寸效果。实验活性将使用传输（超流体密度和热电导率）以及新型的噪声温度计和纳米线作为局部温度计进行探测兴奋。研究人员预计，这种限制和超流体基础状态之间的平衡可以稳定，即保留（3HE-B）或断裂（3HE-A）时间逆转对称性也将受到约束的影响。通过测量限制3HE的相图，将绘制出强耦合强度的压力和温度依赖性的细节，从而允许更可靠地预测3HE的相位图。限制还将提供研究由于批量/边缘对应而产生的表面/边缘兴奋的手段。在受限A和B相之间的一阶转变中（与散装成核的径向不同）中的滞后研究将挑战当前对这些量子转变的理解。新的几何形状将探索跨多个接口和多个接口的量子传输物理。通过将低温和纳米制造结合起来，研究生和本科生将接触到激动人心的训练场，该训练场已经为科学家准备了学术界和高科技行业的主角。最终，在限制下出现的新超级流体可能会引起量子计算的兴趣。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响审查标准，通过评估来诚实地获得支持。