Mesoscopic Superfluid 3He

介观超流体 3He

基本信息

批准号：
EP/E001009/1
负责人：
Andrei Golov
金额：
$ 61.12万
依托单位：
University of Manchester
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2006
资助国家：
英国
起止时间：
2006 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FE001009%2F1
关键词：
Mesoscopic Superfluid 3He

项目摘要

Superfluid 3He is the most ordered and pure condensed matter system, as a result various types of quantized vortices and other defects of its order were observed and studied. When superfluid 3He becomes two-dimensional, new types of vortices are expected. While fundamental on its own, understanding of such vortices paves way to our understanding of unconvensional superconductors and cosmic strings. We will study the vortex physics in superfluid 3He of reduced dimensions. The new research direction can be initiated by using a rare combination of expertise from different research groups in the School of Physics and Astronomy. Golov's group has a long-term experience in studies of superfluid helium and possesses a unique rotating cryostat for creating vortices in superfluid 3He. Geim's group will contribute to the project through its direct access to modern microfabrication facilities and extensive expertise in mesoscopic physics, including the physics of vortices in mesoscopic superconductors. We intend to study quantized vortices in thin slabs of superfluid 3He confined by flat boundaries with artificially fabricated periodic arrays of submicron bumps (pinning centres for vortices). The properties of 3He in thin-slab geometry should differ from those of bulk superfluid in many respects, for example, new type of vortices with circulation equal to just one half of circulation quantum are expected. With our rotating cryostat, we will introduce vortices of required density while keeping the 3He below its superfluid transition temperature of 0.9 mK. With arrays of nanofabricated pinning centres, we expect to observe commensurability effects when densities of the arrays of vortices and pinning centres match. This will provide a direct measure of the vortex density and, among other things, should allow us to find out whether vortices can become fractional under certain experimental conditions.

超流体3He是最有序、最纯净的凝聚态物质系统，因此人们对各种类型的量子化涡旋及其有序缺陷进行了观察和研究。当超流体 3He 变成二维时，预计会出现新型涡流。虽然其本身很重要，但对这种漩涡的理解为我们对非常规超导体和宇宙弦的理解铺平了道路。我们将研究降维超流体 3He 中的涡旋物理。新的研究方向可以通过利用物理与天文学学院不同研究小组的专业知识的罕见组合来启动。 Golov团队在超流氦研究方面拥有长期经验，并拥有独特的旋转低温恒温器，用于在超流3He中产生涡流。海姆的团队将通过直接使用现代微加工设施和介观物理学（包括介观超导体中的涡旋物理学）的广泛专业知识为该项目做出贡献。我们打算研究超流体 3He 薄板中的量子化涡流，该超流 3He 薄板受到平坦边界的限制，并具有人工制造的周期性亚微米凸块阵列（涡流的钉扎中心）。薄板几何中的 3He 的性质在许多方面都与块体超流体不同，例如，预计会出现循环量仅为循环量子二分之一的新型涡流。通过我们的旋转低温恒温器，我们将引入所需密度的涡流，同时将 3He 保持在其超流体转变温度 0.9 mK 以下。通过纳米制造的钉扎中心阵列，我们期望在涡旋阵列和钉扎中心的密度匹配时观察到可通约性效应。这将提供涡旋密度的直接测量，并且除其他外，应该使我们能够找出涡旋在某些实验条件下是否可以变成分数。