CAREER: Engineering artificial oxide layers with hidden spin symmetry for drivable 2D quantum magnetism

职业：设计具有隐藏自旋对称性的人造氧化物层，以实现可驱动的二维量子磁性

• 批准号: 1848269
• 负责人: Jian Liu
• 金额: $ 70.83万
• 依托单位: University of Tennessee Knoxville
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1848269&HistoricalAwards=false
• 关键词: CAREER; Engineering; artificial; oxide; layers

Nontechnical abstract: Magnetic materials have been known and exploited for applications since the ancient times of human history. While their advanced use in modern days can be commonly found in computers and electronics, new magnetic materials are necessary for developing a next generation of processors, memories, and sensors with better security, faster speed, and smaller size. Two-dimensional quantum antiferromagnet holds such promise because of its high scalability in the form of atomic layers. However, antiferromagnets, unlike ferromagnets, intrinsically resist control with a magnetic field. Moreover, realizing two-dimensional magnets is highly challenging because real materials are three dimensional. To overcome these difficulties, it is necessary to develop the capability of material synthesis by design with atomic precision. This research focuses on atomic layering of oxide materials to achieve quantum antiferromagnets that are not only two-dimensional but also externally controllable. Specifically, iridium-based oxides are used to realize a design where the antiferromagnet retains its internal magnetic structure and yet responds to magnetic field in a way similar to a ferromagnet. The project involves a revamp of undergraduate physics course materials, along with an outreach component that specifically targets underrepresented minorities and the general public.Technical abstract: Achieving control of two-dimensional quantum Heisenberg antiferromagnets is not only advancing our understanding of quantum many-body physics but also enables exploitation of quantum effects for new technologies. Realizing efficient external control is however highly challenging because of no direct linear coupling of an external magnetic field to the antiferromagnetic order. Moreover, internal spin anisotropy and three-dimensional coupling are always present in real materials, suppressing the two-dimensional critical fluctuations. While these barriers are difficult to overcome in bulk materials, the principle investigator plans to employ in-situ-monitored pulsed-laser deposition growth to construct a variety of atomically thin epitaxial oxide layers with strong spin-orbit coupling that creates large anisotropic exchange interactions and spin canting but preserves the spin rotational symmetry. The resulting two-dimensional quantum antiferromagnetic lattices is expected to be in close proximity to the spin isotropic limit and exhibits iant responses to applied external fields. This unique mechanism can be implemented by engineering the thicknesses, structural distortions, composition, and strain state of the oxide layers through epitaxial growth. An important goal is to unveil the two-dimensional critical fluctuations near quantum phase transitions, and to establish external controls of the antiferromagnetic order parameter via a suite of characterization techniques, including advanced synchrotron x-ray scattering and spectroscopy. The results are expected to facilitate the development of functional two-dimensional quantum antiferromagnets.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.

非技术摘要：自从人类历史上的古代以来，磁性材料已被众所周知和利用。虽然它们在现代的高级用途通常可以在计算机和电子设备中找到，但对于开发下一代处理器，记忆和传感器，具有更好安全性，更快速度和较小尺寸的传感器是必需的。二维量子抗铁磁铁具有这样的希望，因为它以原子层的形式具有很高的可扩展性。 但是，与铁磁体不同，抗铁磁体本质上可以用磁场抵抗对照。此外，意识到二维磁铁是高度挑战性的，因为实际材料是三维的。为了克服这些困难，有必要通过原子精度来发展材料合成的能力。这项研究的重点是氧化物材料的原子分层，以实现不仅是二维，而且在外部可控的量子抗铁磁铁。具体而言，基于虹膜的氧化物用于实现一种设计，在该设计中，抗铁磁铁保留其内部磁性结构，但以类似于Ferromagnet的方式对磁场做出反应。该项目涉及本科物理学课程材料的改革，以及专门针对代表性不足的少数群体和公众的外展成分。技术摘要：控制二维量子Heisenberg Heisenberg AntiferRomagnets的控制不仅是对量子多种物理学的理解，还可以增强量子型的理解。但是，实现有效的外部控制是高度挑战性的，因为外部磁场没有直接的线性耦合与抗铁磁序列。此外，内部自旋各向异性和三维耦合始终存在于真实材料中，从而抑制了二维临界波动。尽管这些障碍在大量材料中很难克服，但主要研究者计划采用原位监测的脉冲激光沉积生长生长来构建具有强大的自旋轨道耦合的各种原子上薄的外在氧化物层，从而创造了较大的自旋轨道耦合，从而构成了大型的型反应型交易所相互作用和旋转倾斜，但可以保留旋转的旋转对称性。预计所得的二维量子抗铁磁晶格将与自旋各向同性极限紧密接近，并表现出对所应用外部场的IANT响应。可以通过外延生长来设计氧化物层的厚度，结构扭曲，组成和应变状态来实现这种独特的机制。一个重要的目标是通过一系列特征技术（包括高级同步X射线散射和光谱法），揭示量子相变附近的二维临界波动，并建立对抗磁性顺序参数的外部控制。结果有望促进功能性二维量子抗铁磁铁的发展。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响审查标准，被认为值得通过评估来获得支持。

项目成果

Laser-induced transient magnons in Sr3Ir2O7 throughout the Brillouin zone

• DOI: 10.1073/pnas.2103696118
• 发表时间: 2020-02
• 期刊: Proceedings of the National Academy of Sciences
• 作者: D. Mazzone;D. Meyers;Yue Cao;J. G. Vale;C. D. Dashwood;Youguo Shi;A. James;N. Robinson;Jiaqi Lin;V. Thampy;Yoshikazu Tanaka;Allan S. Johnson;H. Miao;Ruitang Wang;Tadesse A. Assefa;Jungho Kim;D. Casa;R. Mankowsky;D. Zhu;R. Alonso-Mori;Sanghoon Song;H. Yavas;T. Katayama;M. Yabashi;Y. Kubota;S. Owada;Jian Liu;Junji Yang;R. Konik;I. Robinson;John P. Hill;D. McMorrow;M. Först;S. Wall;Xuerong Liu;M. Dean

Strongly anisotropic antiferromagnetic coupling in EuFe2As2 revealed by stress detwinning

• DOI: 10.1103/physrevb.104.104413
• 发表时间: 2020-12
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Joshua J. Sanchez;G. Fabbris;Yongseong Choi;Yue Shi;P. Malinowski;Shashi Pandey;Jian Liu;I. Mazin;Jong-Woo Kim;P. Ryan;J. Chu

Single-Laser-Pulse-Driven Thermal Limit of the Quasi-Two-Dimensional Magnetic Ordering in Sr2IrO4

• DOI: 10.1103/physrevx.11.041023
• 发表时间: 2021-10
• 期刊: Physical Review X
• 影响因子: 12.5
• 作者: Ruitang Wang;J. Sun;D. Meyers;J. Lin;J. Yang;G. Li;H. Ding;A. DiChiara;Y. Cao;J. Liu;M. Dean;H. Wen;X. Liu

Suppression of superconductivity by anisotropic strain near a nematic quantum critical point

• DOI: 10.1038/s41567-020-0983-9
• 发表时间: 2020-08-10
• 期刊: NATURE PHYSICS
• 影响因子: 19.6
• 作者: Malinowski, Paul;Jiang, Qianni;Chu, Jiun-Haw
• 通讯作者: Chu, Jiun-Haw

Epitaxial growth and antiferromagnetism of Sn-substituted perovskite iridate SrIr0.8Sn0.2O3

• DOI: 10.1103/physrevmaterials.3.124411
• 发表时间: 2019-12
• 期刊: arXiv: Materials Science
• 作者: Junyi Yang;L. Hao;Q. Cui;Jiaqi Lin;L. Horák;Xuerong Liu;Lu Zhang;Huaixin Yang;J. Karapetrova;Jong-Woo Kim;P. Ryan;M. Dean;Jinguang Cheng;Jian Liu