MRI: Development of a Cryogenic Integrated Micro-Raman-Brillouin-Mandelstam Spectrometer

非技术描述：这个主要的研究仪器（MRI）开发项目旨在建立一个集成的微拉曼-布里温-曼德尔施塔姆光谱仪系统，该系统具有低温保存样品的能力。拉曼散射和布里渊-曼德尔斯塔姆散射是一种非弹性光散射过程，用于测量固体材料中各种元素激发（如声子和磁振子）的能量。声子是晶格振动的量子，它与固体的声速有关，也在材料的电学、热学和光学现象中表现出来。磁振子是电子自旋波的量子，它决定了磁性材料的特性。在低温下进行测量的能力对于研究磁性材料尤为重要。光谱仪的光谱范围和设计允许它用于小尺寸和厚度的样品。该项目为布里渊光谱仪器的发展提供了动力，并将其提升到目前拉曼光谱所享有的水平。通过光谱系统获得的信息有助于新材料的合成和表征，并有助于更好地了解其性质。该仪器提高了研究竞争力，并加强了加州大学河滨分校的科学和工程教育，这是一所经认证的西班牙裔服务机构。技术描述：微拉曼-布里温-曼德尔斯塔姆光谱仪系统的特点使其成为一个多用户的设施，并使科学和工程研究人员从大学和工业界进行广泛的主题研究：从前沿的基础固体物理的磁振子，声子和非平凡拓扑状态的工程测量的复合材料的弹性常数。该系统的先进特点包括：(i)一个专门设计的旋转显微镜台和成像系统，用于测量声子、磁振子和其他元素激发在4 K至700 K温度范围内的能量色散；（ii）样品具有较高的空间分辨率，原子厚度，磁振子的横向尺寸约为250纳米，声子的横向尺寸约为1微米；（iii）用于记录声子和磁振子能量的模量大大低于目前传统光谱仪的1 ghz限制；(4)具有高时空分辨率的相干声子和磁振子同时激发和观测的平台。研究横向尺寸在微米范围内的原子薄膜的可能性使研究人员能够测量声子能量色散。该系统的能力提供了二维和一维材料中的声子和磁振子的基本知识；磁性材料中磁子-声子和自旋晶格相互作用的强度低维材料中的弹性常数、声子速度和Gruneisen参数；量子材料中的电荷密度波；以及其他准粒子在新材料、异质结构和生物系统中的特性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Nontechnical Description:This major research instrumentation (MRI) development project aims to build an integrated micro-Raman-Brillouin-Mandelstam spectrometer system with a capability for samples held at cryogenic temperatures. Raman scattering and Brillouin-Mandelstam scattering are inelastic light scattering processes, which are used to measure energies of various types of elemental excitations, such as phonons and magnons, in solid materials. Phonons are quanta of crystal lattice vibrations, which are associated with sound velocities of solids and also reveal themselves in electrical, thermal and optical phenomena in materials. Magnons are quanta of electron spin waves, which determine characteristics of magnetic materials. The capability of conducting measurements at low temperatures is particularly important for studying magnetic materials. The spectral range and design of the spectrometer allow for its use for samples of small dimensions and thicknesses. The project provides an impetus to development of the Brillouin spectroscopy instrumentation, and its elevation to the level currently enjoyed by Raman spectroscopy. Information obtained with the spectroscopy system facilitates synthesis and characterization of new materials, and helps in better understanding of their properties. The instrument increases research competitiveness and enhances science and engineering education at the University of California - Riverside, which is an accredited Hispanic Serving Institution. Technical Description:The characteristics of the micro-Raman-Brillouin-Mandelstam spectrometer system make it a multi-user facility, and enable science and engineering researchers from universities and industry to conduct studies in a wide range of topics: from the cutting-edge fundamental solid-state physics of magnons, phonons and non-trivial topological states to engineering measurements of the elastic constants of composites. The advanced features of the system include (i) a specially designed rotating microscopy stage and imaging system for measuring the energy dispersion of phonons, magnons, and other elemental excitations in the temperature range from 4 K to 700 K; (ii) a high spatial resolution for the samples with the atomic thickness, lateral dimensions approximately 250 nanometers for magnons and about 1 micrometer for phonons; (iii) a modulus for recording phonon and magnon energies substantially below the current 1-GHz limit of conventional spectrometers; and (iv) a stage for simultaneous excitation and observation of coherent phonons and magnons with high spatial and temporal resolution. The possibility of investigating atomically-thin films with lateral dimensions in the micrometer range allows researchers to measure acoustic phonon energy dispersion. The capabilities of the system provide fundamental knowledge of phonons and magnons in two-dimensional and one-dimensional materials; the strength of the magnon-phonon and spin-lattice interactions in magnetic materials; elastic constants, phonon velocities and Gruneisen parameters in low-dimensional materials; charge density waves in quantum materials; as well as characteristics of other quasiparticles in novel materials, heterostructures and biological systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.