MRI: Acquisition of Cryogen-Free High Magnetic Field Physical Property Measurement System

非技术摘要：量子材料是融合多学科发展下一代电子和能源技术的新兴领域。量子材料的一个众所周知的例子是高温超导体，它带来了不损失能量的电力传输的希望。获得无低温物理性能测量系统（PPMS）使密歇根大学的研究人员能够测量下一代材料的性能。从量子材料的研究中获得的基本理解为未来的电子产品奠定了基础，包括高密度硬盘驱动器、量子计算机和利用太阳能或汽车发动机废热发电的半导体面板。PPMS为培养研究生和本科生提供了极好的途径。学生使用最先进的设备进行研究，并在跨学科的环境中接受教育和培训。PPMS允许本科生和高中生与研究者一起做研究，以及那些参加高级物理实验课程的学生，在低温下轻松安全地进行实验。研究人员利用现有的REU和博士衔接课程，从代表性不足的群体中吸引学生参与量子电子材料项目，这将增强未来美国STEM劳动力的多样性。技术摘要：获得具有14特斯拉磁体的无低温物理性质测量系统（PPMS），使密歇根大学能够研究新型量子材料，以回答以下重要问题。（1）. 通过强电子相关、界面工程和边缘谷极化，在二维电子系统中可以实现哪些基本的新物理和新功能？（2）. 为什么最著名的3D狄拉克电子系统是好的热电材料？(3)。决定稀化半导体合金光电性能的关键参数是什么？(4)。在传统和新型半导体中，自旋与电子自由度是如何耦合的？为了回答这些基本问题，研究范围包括：(1)新兴的二维电子系统；(2)三维狄拉克电子系统中的增强型热电材料；(3)半导体合金的物理性质；(4)半导体的自旋和磁性。研究的方法和途径探索了广泛的物理性质，包括电阻率、霍尔效应、磁化、热容量、交流磁化率、导热系数和热功率。这些研究有助于理解物理机制，并为量子材料的重要和新颖应用奠定基础。

Non-technical abstract:Quantum materials are an emergent field integrating many science disciplines to develop next generation electronic and energy technology. A well-known example of quantum materials is the high temperature superconductor, which brings promise of electricity transfer without energy loss. The acquisition of the cryogen-free Physical Properties Measurement System (PPMS) enables researchers at the University of Michigan to measure the properties of next-generation materials. The fundamental understanding gained from the study of quantum materials lays the foundation for future electronics, including high-density hard drives, quantum computers, and semiconductor panels that generate electricity using solar energy or waste heat from your car engine. The PPMS provides excellent avenues for training graduate and undergraduate students. The students perform research using state-of-the-art equipment and receive education and training in an interdisciplinary environment. PPMS allows undergraduate and high school students, doing research with the investigators, and those taking upper level physics laboratory courses, to easily and safely perform experiments at cryogenic temperatures. The investigators leverage existing REU and bridge-to-PhD programs to bring in students from underrepresented groups to participate in projects on quantum electronic materials, which enhance the diversity of the future US STEM workforce. Technical Abstract:The acquisition of a cryogen-free Physical Properties Measurement System (PPMS) with a 14 Tesla magnet enables studies of novel quantum materials at the University of Michigan in order to answer the following important problems. (1). What fundamentally new physics and novel functionalities can be achieved in 2D electronic systems by strong electronic correlations, interface engineering, and edge valley polarization? (2). Why are the most well known 3D Dirac electronic systems good thermoelectric materials? (3). What are the key parameters determining the optoelectronic properties of dilute semiconductor alloys? (4). How are spins coupled to the electronic degrees of freedom in conventional and novel semiconductors? Aiming to answer these fundamental questions, the scope of research includes: (1) Emergent novel two-dimensional electronic systems, (2) Enhanced Thermoelectric materials in 3D Dirac electronic systems, (3) Physical properties of Semiconductor Alloys, and (4) Manipulating spin and magnetic properties in semiconductors. The methods and approaches of the research explore a broad range of physical properties including resistivity, Hall effect, magnetization, heat capacity, AC susceptibility, thermal conductivity, and thermopower. The studies enable understanding of physical mechanisms, and lay the foundation for important and novel applications of quantum materials.