Superfluid Dynamics of Quantum Ferrofluids

量子铁磁流体的超流体动力学

• 批准号: EP/M005127/1
• 负责人: Nicholas Parker
• 金额: $ 12.76万
• 依托单位: Newcastle University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FM005127%2F1
• 关键词: Superfluid; Dynamics; Quantum; Ferrofluids

In state-of-the-art laboratories worldwide, gases of atoms are being cooled down to temperatures less than a millionth of a degree above absolute zero. At this extreme coldness, quantum mechanics takes over; the atoms lose their individual identities and become smeared out into a giant wave of matter. This quantum gas hosts a range of bizarre behaviours, from its capacity to undergo wave-like interference to its embodiment of a superfluid, a fluid with no resistance to motion. The quantum gas is far from just a scientific curiosity. It represents a clean and pure exemplar of a many-particle quantum system, giving rich insight into the quantum world. Atomic physics techniques empower experimentalists to precisely tune its physical properties and manipulate it in time and space. Due to these facets, quantum gases are being exploited as "emulators" to recreate and understand complicated physical phenomena, from superconductors and turbulence to black holes and the Big Bang. The quantum gas also holds exciting technological prospects. Their exceptional sensitivity to being disturbed is driving their development as ultra-precise sensors, e.g. of gravity, for which they are touted to lead to major advancement in oil and mineral exploration. Meanwhile, their unprecedented quantum control makes these gases candidates for performing quantum gate operations, the basis of the much-lauded quantum computer.Recent experiments in quantum gases have created a "quantum ferrofluid". Being both a superfluid and a ferrofluid, this novel state lies at the interface of two of our most bizarre fluids. Ferrofluids are liquids dispersed with tiny magnetic iron particles. Just like bar magnets, the particles interact over long-range, prefer to lie with north and south poles being adjacent, and become aligned in an imposed magnetic field. This leads to peculiar patterns and instabilities in the fluid, but, more importantly, enables the flow and physical properties to be controlled via magnetic fields, as exploited in ferrofluid technologies in medicine, information display and sealants. The quantum sibling of the ferrofluid, the quantum ferrofluid, has been formed from an ultracold quantum gas of magnetic atoms. This gas is being hotly researched to probe its novel properties and potential exploitation. Its magnetic nature extends the above-mentioned capabilities of the quantum gas into new territories, e.g., providing a testbed of quantum magnetism, emulation of systems with long-range interactions, and a sensitivity to magnetic fields which can be exploited in a new generation of magnetic sensors, with potential applications from geological exploration to military detection. Meanwhile, the long-range magnetic interaction between atoms is particularly attractive for quantum computation since it allows the computational operations to be performed at a distance. The fundamental nature of superfluidity in the quantum ferrofluid remains uncharted, and uncovering it is the core aim of this project. With superfluidity underpinning the transport properties of the system, we will reveal how the quantum ferrofluid moves and flows, swirls and gyrates, and responds to agitation. This is of fundamental interest to our understanding of superfluidity in general, but, more specifically, is of great practical benefit for future manipulation and exploitation of the quantum ferrofluid. The distinctive behaviour of conventional ferrofluids and their virtuous control via magnetic fields is suggestive of a rich plethora of novel superfluid behaviour and a new dimension of control over the superfluid state. The quantum ferrofluid may in turn provide insight into the conventional ferrofluid; being superfluid, with an absence of viscosity, the quantum ferrofluid embodies a simplified version of the ferrofluid from which outstanding problems in ferrofluids can be tackled afresh.

在世界各地最先进的实验室里，原子气体被冷却到绝对零度以上不到百万分之一度的温度。在这种极端的寒冷中，量子力学接管了一切;原子失去了它们的个体身份，变成了一个巨大的物质波。这种量子气体具有一系列奇异的行为，从它经历波动干涉的能力到它的超流体的体现，一种对运动没有阻力的流体。量子气体远不只是科学上的好奇心。它代表了多粒子量子系统的一个干净而纯粹的范例，为量子世界提供了丰富的见解。原子物理学技术使实验者能够精确地调整其物理特性并在时间和空间中操纵它。由于这些方面，量子气体正被用作“仿真器”来重现和理解复杂的物理现象，从超导体和湍流到黑洞和大爆炸。量子气体也具有令人兴奋的技术前景。它们对干扰的特殊敏感性推动了它们作为超精密传感器的发展，例如重力传感器，它们被吹捧为石油和矿产勘探的重大进步。与此同时，它们前所未有的量子控制能力使这些气体成为执行量子门操作的候选者，量子门操作是备受赞誉的量子计算机的基础。最近的量子气体实验创造了一种“量子铁磁流体”。作为一种超流体和铁磁流体，这种新的状态位于我们两种最奇怪的流体的界面上。铁磁流体是分散有微小磁性铁颗粒的液体。就像条形磁铁一样，粒子在长距离上相互作用，更喜欢与北极和南极相邻，并在施加的磁场中对齐。这导致流体中的特殊模式和不稳定性，但更重要的是，使流动和物理特性能够通过磁场控制，如在医学，信息显示和密封剂中的铁磁流体技术中所利用的。 铁磁流体的量子兄弟，量子铁磁流体，是由磁性原子的超冷量子气体形成的。人们正在对这种天然气进行研究，以探索其新的性质和潜在的开发利用。它的磁性性质将量子气体的上述能力扩展到新的领域，例如，提供了一个量子磁性的测试平台，具有远程相互作用的系统的仿真，以及对磁场的灵敏度，这些可以在新一代磁传感器中开发，具有从地质勘探到军事探测的潜在应用。与此同时，原子之间的长程磁相互作用对于量子计算特别有吸引力，因为它允许计算操作在远处进行。量子铁磁流体中超流性的基本性质仍然是未知的，揭示它是这个项目的核心目标。随着超流性支撑系统的传输特性，我们将揭示量子铁磁流体如何移动和流动，漩涡和旋转，并对搅动作出反应。这对我们理解超流性具有根本意义，但更具体地说，对未来操纵和开发量子铁磁流体具有巨大的实际好处。传统铁磁流体的独特行为及其通过磁场进行的良性控制暗示了丰富的新型超流行为和超流状态控制的新维度。量子铁磁流体可以反过来提供对传统铁磁流体的洞察;作为超流体，没有粘性，量子铁磁流体体现了铁磁流体的简化版本，可以重新解决铁磁流体中的突出问题。

项目成果

Probing quasi-integrability of the Gross-Pitaevskii equation in a harmonic-oscillator potential

探讨谐波振荡器势中 Gross-Pitaevskii 方程的准可积性

• DOI: 10.1088/1361-6455/aae0ba
• 发表时间: 2018
• 期刊: Atomic, Molecular and Optical Physics
• 作者: Bland T

Quantum droplets of quasi-one-dimensional dipolar Bose-Einstein condensates

准一维偶极玻色-爱因斯坦凝聚体的量子液滴

• DOI: 10.48550/arxiv.2002.07958
• 发表时间: 2020
• 作者: Edmonds M

Controllable non-local interactions between dark solitons in dipolar condensates

偶极凝聚中暗孤子之间的可控非局域相互作用

• DOI: 10.48550/arxiv.1509.00615
• 发表时间: 2015
• 作者: Bland T

Controllable nonlocal interactions between dark solitons in dipolar condensates

• DOI: 10.1103/physreva.92.063601
• 发表时间: 2015-09
• 期刊: Physical Review A
• 影响因子: 2.9
• 作者: Thomas Bland;M. Edmonds;N. Proukakis;A. M. Martin;D. O'Dell;N. Parker

Anomalous oscillations of dark solitons in trapped dipolar condensates

俘获偶极凝聚体中暗孤子的反常振荡

• 发表时间: 2016
• 作者: []