Super-Diffusion In Quantum Spin Chains

量子自旋链中的超扩散

• 批准号: EP/X011887/1
• 负责人: Mingee Chung
• 金额: $ 42.74万
• 依托单位: University of Birmingham
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FX011887%2F1
• 关键词: Super; Diffusion; Quantum; Spin; Chains

A drop of ink in a glass of water will diffuse outwards with time, eventually colouring the whole of the water homogeneously. A ball on a billiard board, on the other hand, will roll around, colliding and scattering off other balls. Transport of mass, energy or other properties in nature seem to occur predominantly in either way, called diffusive and ballistic, respectively. They constitute our intuition into the natural world and universe. However, physicists suspect that there could be other new types of transport defying our common sense. For instance, the transport of magnetic fluctuations in certain materials could occur neither diffusively nor ballistically, but somewhat intermediate. This unconventional transport is called the super-diffusion and is predicted to occur in one-dimensional quantum magnetic materials. It is also exciting that such unconventional transport could occur at room temperature in contrast with our naïve expectation that unique behaviour from quantum systems should be only observed at extremely low temperature. This could be a useful aspect for potential application such as in Spnitronics. In this research project, I aim to provide the first clear experimental evidence for super-diffusion in quantum magnets. More specifically, I will look into crystals where magnetic ions are predominantly coupled along one direction, rather than three directions. This allows the crystals essentially behave as a collection of one-dimensional chain of magnetic ions. I will use Nuclear Magnetic Resonance (NMR) technique, akin to MRI, to evidence that the transport of magnetic fluctuations in such one-dimensional quantum chain occurs as super-diffusion. Through this research, we will be able to better understand the properties of quantum materials, which will underpin the development of new quantum technologies such as quantum sensors or computers.

一杯水中的一滴墨水会随着时间向外扩散，最终将整个水均匀地着色。另一方面，台球板上的球会滚来滚去，碰撞并散落在其他球上。自然界中的质量、能量或其他性质的传输似乎主要以任何一种方式发生，分别称为扩散和弹道。它们构成了我们对自然世界和宇宙的直觉。然而，物理学家怀疑，可能会有其他违反常识的新型交通工具。例如，磁涨落在某些材料中的传输既不是扩散的，也不是弹道的，而是在某种程度上是中间的。这种非传统的输运被称为超扩散，预计将发生在一维量子磁性材料中。同样令人兴奋的是，这种非常规输运可以在室温下发生，而我们天真的期望是，只有在极低的温度下才能观察到量子系统的独特行为。这可能是潜在应用的一个有用的方面，例如在Spnitronics中。在这个研究项目中，我的目标是为量子磁铁中的超扩散提供第一个明确的实验证据。更具体地说，我将研究磁性离子主要沿一个方向而不是三个方向耦合的晶体。这使得晶体基本上表现为一维磁性离子链的集合。我将使用核磁共振(核磁共振)技术，类似于核磁共振，来证明这种一维量子链中磁涨落的传输是以超扩散的形式发生的。通过这项研究，我们将能够更好地了解量子材料的性质，这将为量子传感器或计算机等新量子技术的发展奠定基础。