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.

一滴墨水在一杯水中会随着时间的流逝而向外扩散，最终使整个水均匀地着色。另一方面，台球板上的球将滚动，碰撞并散射其他球。自然界中质量，能量或其他特性的运输似乎主要以两种方式发生，分别称为扩散和弹道。它们构成了我们进入自然世界和宇宙的直觉。但是，物理学家怀疑可能还有其他新型运输违背我们的常识。例如，某些材料中磁波动的运输可能会有所不同，也可能是弹道的，但有些是中间的。这种非常规的运输称为超扩散，预计将发生在一维量子磁性材料中。同样令人兴奋的是，这种非常规的运输可能在室温下发生，与我们幼稚的期望，即只能在极低的温度下观察到量子系统的独特行为。对于潜在应用，例如在Spnitronics中，这可能是一个有用的方面。在该研究项目中，我旨在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，我将研究磁离子主要沿一个方向耦合而不是三个方向的晶体。这允许晶体基本上作为一维磁离子链的集合。我将使用类似于MRI的核磁共振（NMR）技术，证明这种一维量子链中磁波的运输是作为超扩散的。通过这项研究，我们将能够更好地理解量子材料的特性，这将支持新的量子技术（例如量子传感器或计算机）的开发。