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-布里渊-曼德尔斯塔姆光谱仪系统，能够在低温下保存样品。拉曼散射和布里渊-曼德尔斯坦散射都是非弹性光散射过程，用于测量固体材料中各种元素激发的能量，如声子和磁子。声子是晶格振动的量子，它与固体的声速有关，也显示在材料的电学、热学和光学现象中。磁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特别重要。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。该项目推动了布里渊光谱仪器的发展，并将其提升到目前拉曼光谱所享有的水平。利用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它们的性质。该仪器提高了加州大学河滨分校的研究竞争力，并加强了科学和工程教育，该大学是一家经认可的拉美裔服务机构。技术说明：微拉曼-布里渊-曼德尔斯塔姆光谱仪系统的特点使其成为一种多用户设备，使来自大学和工业的科学和工程研究人员能够在一系列主题中进行研究：从磁子、声子和非平凡拓扑态的尖端基本固态物理到复合材料弹性常数的工程测量。该系统的先进特征包括：(I)专门设计的旋转显微镜工作台和成像系统，用于在4K至700K的温度范围内测量声子、磁子和其他元素激发的能量色散；(Ii)对原子厚度的样品具有高空间分辨率，横向尺寸约为250纳米，声子约为1微米；(Iii)用于记录声子和磁振子能量的模块，大大低于目前传统光谱仪的1 GHz限制；以及(Iv)用于同时激发和观测高空间和时间分辨率的相干声子和磁子的工作台。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学声子能量色散。该系统的能力提供了二维和一维材料中的声子和磁子的基本知识；磁性材料中的磁振子和自旋晶格相互作用的强度；低维材料中的弹性常数、声子速度和格吕内森参数；量子材料中的电荷密度波；以及新材料、异质结构和生物系统中的其他准粒子的特征。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.