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

基本信息

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

项目摘要

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.

非技术摘要大多数消费品都利用因凝聚态研究的进步而出现的技术，未来的进步将通过对仅在实验室环境中才能进行的新机制的“好奇心驱动”探索来实现。将研究超流体 3He 在高度小于千分之一毫米的精确定义结构中的特殊性质，标志着从所谓的大块 3 维行为到新的 2 维状态的转变。博士生将利用尖端知识来设计和制造这些结构，开辟量子纳米流体的新领域，因为光滑度（可通过氦涂层改变）必须具有明确的光滑度。 4）改变表面的散射，就像镜面与磨砂表面不同一样，这种散射质量（与限制一起）也可以改变出现的超流体状态（“相”）的类型。财产“手性”应该具有像旋转陀螺一样的特性，这些新相应该表现出新颖的特性，例如在科学上“令人兴奋”的高导电“边缘态”，并且可能在未来形成新型计量设备的基础。该团队过去的研究生和本科生已在学术界、高科技行业和金融领域从事富有成效的职业，计划中的研究将为新一代学生做好迎接挑战的职业的准备。技术摘要：Superfluid 3He can。告知研究活动该项目将纳米流体（复杂且精确制造的硅腔，其尺寸调整为超流体的相干长度）与低温物理学相结合，以揭示新的尺寸效应。研究人员预计，全新的 p 波超流体状态可以通过这种限制和之间的平衡来稳定。保持 (3He-B) 或破坏 (3He-A) 时间反演对称性的超流体基态也会受到约束的影响。通过测量约束 3He 的相图，强耦合强度的压力和温度依赖性的细节将受到约束。绘制出允许更可靠地预测约束下 3He 相图的方法，也将提供研究由于体/边缘对应研究而出现的表面/边缘激发的方法。受限 A 相和 B 相之间的一阶转变（与块体成核完全不同）中的滞后现象将挑战当前对这些量子转变的理解，新的几何结构将通过结合低温来探索跨单个和多个界面的量子传输物理学。和纳米制造，研究生和本科生将接触到令人兴奋的训练场，为科学家在学术界和高科技行业中发挥领导作用做好准备，最终，在限制下出现的新超流体可能会引起量子领域的兴趣。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。