MRI: Acquisition of Helium Recovery Equipment For Time-Resolved ARPES at NSF-NeXUS

MRI：在 NSF-NeXUS 采购用于时间分辨 ARPES 的氦回收设备

• 批准号: 2320634
• 负责人: Roland Kawakami
• 金额: $ 15.83万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2320634&HistoricalAwards=false
• 关键词: MRI; Acquisition; Helium; Recovery; Equipment

This MRI award funds the acquisition of an ultralow temperature refrigerator for cooling samples down to a temperature of 10 Kelvin (-440 degrees F, -260 degrees C) at the NSF-NeXUS (National Extreme Ultrafast Science) mid-scale facility, an open-access ultrafast laser user facility at the Ohio State University. Many of the most interesting phenomena in quantum materials occur at these very low temperatures, so this is a critical component for enabling a broad range of experiments. This project brings together a group of leading scientists in two-dimensional materials, chiral materials, magnetic materials, and topological materials, who are part of the first experiments and initial user base. Education and outreach activities highlight these advanced instruments, their scientific value, and societal impacts to audiences ranging from researchers in adjacent disciplines to graduate and undergraduate students.The goal of this research is to understand the dynamics of electron waves in quantum materials, which could lead to faster and more energy-efficient electronics and advanced quantum technologies. This is enabled by newly developed experimental techniques that directly image electron dynamics in time, space, energy, and momentum at the NeXUS mid-scale facility. The use of momentum microscopy (MM) and high-harmonic generation light sources produces a major advance in time-resolved, angle-resolved photoemission spectroscopy (TR-ARPES) by adding spatial resolution (~2 microns) and full Brillouin zone mapping. This enables pump-probe studies of carrier, exciton, and band structure dynamics in a variety of interesting quantum materials including two-dimensional materials (transition metal dichalcogenides, graphene, twisted moiré heterostructures, etc), topological materials with Dirac cones away from the gamma point, and chiral and magnetic materials for spintronics. Researchers on this project are utilizing the combined energy-, momentum-, spatial- and temporal-resolution of MM-based TR-ARPES to investigate and understand exciton relaxation processes, charge transfer in heterostructures, valley dynamics, and correlated ground states, as well as light-induced phase transitions and the dynamic manipulation of band structures and Berry curvature. The addition of the new closed-cycle cryocooler to the NeXUS TR-ARPES beamline enables the systematic variation of sample temperature down to 10 K, which is critical for studying exotic phases of quantum materials and also understanding the role of phonons on the dynamics.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.

该MRI奖为在NSF-Nexus（National Extremultrafast Science）中尺度的NSF-Nexus（国家非常超快科学）设施（一家开放式超级法斯特Laser-laser-Starnity at ohio Ohio ohio ohio ohio ohio ohio ohio ohio ohio ohio ohio ohio a Ohio ohio a Ohio aimio奖励，以冷却样品（-440摄氏度）的温度（-440度F，-260摄氏度）的获得资金。量子材料中许多最有趣的现象发生在这些非常低的温度下，因此这是实现广泛实验的关键组成部分。该项目汇集了一组领先的科学家，这些科学家是二维材料，手性材料，磁性材料和拓扑材料，这些材料和拓扑材料是第一个实验和初始用户群的一部分。教育和外展活动突出了这些高级工具，它们的科学价值以及对受众的社会影响，从邻近学科的研究人员到毕业和本科生。这项研究的目的是了解量子材料中电子波的动态，这些动态可能会导致更快，能源高效的电子和高级量子技术。这是通过新开发的实验技术来实现的，该技术在Nexus中期设施的时间，空间，能量和动量中直接成像电子动力学。通过添加空间分辨率（〜2微米）和完整的Brillouin区域映射，使用动量显微镜（MM）和高谐波生成光源在时间分辨，角度分辨光发射光谱（TR-ARPE）方面产生了重大进步。这可以在各种有趣的量子材料中对载体，令人兴奋的和带结构动力学进行泵探针研究，包括二维金属二进制二色元，石墨烯，扭曲的moiré莫伊尔异质结构等），拓扑材料，远离伽玛点的狄拉克锥，以及gamma Point，以及用于纺纱的呼射和磁性材料。该项目的研究人员正在利用基于MM的TR-arpes的能量，动量，空间和临时分辨率来调查和理解令人兴奋的放松过程，异质结构中的电荷转移，谷化动力学以及相关的基础状态以及相关的基础状态，以及光诱导的相位过渡以及光线结构和浆液结构和浆果曲线的动态操纵。 The addition of the new closed-cycle cryocooler to the NeXUS TR-ARPES beamline enables the systematic variation of sample temperature down to 10 K, which is critical for studying exotic phases of quantum materials and also understanding the role of phrases on the dynamics.This award reflects NSF's statutory mission and has been deemed precious of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.