A New Window for the Control and Measurement of Quantum Systems

该项目旨在为量子物质中的磁性创造一种新型实验探针，使我们能够同时创造和测量新的量子态。我们的创新将磁光克尔效应（MOKE）技术与低温高压方法相结合，产生新的HP-LT-MOKE测量系统。MOKE是一种光学技术，传统上用于研究薄膜器件的磁性。高压技术具有广泛的应用，可以以可控的方式改变许多材料的特性，包括一系列量子现象和相位。材料的性质受到高压的强烈改变。施加压力使原子靠得更近，这样做不仅可以改变材料的原子晶体结构，还可以改变它们的电子和磁性。我们可以采用压力“量子调谐”，即施加在样品上的压力可以干净而精确地“推动”材料进入在环境条件下不易观察到的新物质状态，或者可以微妙地改变性质，例如半导体中的带隙。所产生的状态的性质与晶体结构以及系统中磁性和电子秩序的性质有着内在的联系。由于在量子临界点附近可能出现非常规超导性、非费米液体行为和其他奇异现象，对铁磁边界的研究引起了人们极大的兴趣。这些影响在理论上具有重大意义，而且与磁记录、磁制冷和能源技术等有关，具有实际意义。

The project aims to create a new type of experimental probe for magnetism in quantum matter which will enable us to simultaneously create and measure new quantum states. Our innovation will combine the technique of magneto-optic Kerr effect (MOKE) with high pressure methods at low temperatures producing a new HP-LT-MOKE measurement system. MOKE is an optical technique traditionally used for the study of magnetic properties of thin film devices. High pressure techniques have a wide range of applications and can alter many material properties in a controlled way including a range of quantum phenomena and phases. The properties of materials are strongly modified by high pressure. Applying pressure pushes the atoms closer together and in so doing can alter not only the materials' atomic crystal structure, but also change their electronic and magnetic properties. We can employ pressure "quantum tuning" in which the pressure applied to samples can be used to cleanly and precisely "push" materials into new states of matter which cannot be readily observed at ambient conditions, or can subtly change properties, such as the band gap in semiconductors. The nature of the states produced is intrinsically linked to the crystal structure and the nature of the magnetic and electronic order in the system. The study of the border of ferromagnetism is of great interest due to the possibility of unconventional superconductivity, non-Fermi liquid behaviour and other exotic phenomena near quantum critical points. The effects are both theoretically significant and of practical importance being relevant to, for example magnetic recording, magnetic refrigeration and energy technologies.