Manipulating the strong quantum spin fluctuations in triple perovskites with effective spin-1/2 triangular lattice

利用有效自旋 1/2 三角晶格操纵三重钙钛矿中的强量子自旋涨落

• 批准号: 2003117
• 负责人: Haidong Zhou
• 金额: $ 39万
• 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: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2003117&HistoricalAwards=false
• 关键词: Manipulating; strong; quantum; spin; fluctuations

Non-technical Abstract:While the rise of quantum computers may one day help solve complex problems and deliver information with unhackable security, there is lack of a material platforms for scalable realization of quantum technologies. For instance, the most interesting magnetic property of the celebrated quantum spin liquids (QSLs) is the possibility of quantum mechanical encryption and transport of information, protected against environmental influences. Despite extensive studies on QSLs, they are still far away from applications. First obstacle is the shortage of understanding of this new phase of matter. The common belief is that the strong quantum spin fluctuations (QSFs) play a critical role in QSLs but how exactly QSFs lead to QSL state or other exotic quantum magnetic phenomena is not clear. Second obstacle is that most of the studied QSLs are insulators and electronically inert, which is incompatible with an electrical circuit that relies on moving charge carriers. The grand challenge is to find a way to convert the entanglement information into mobile charge signal by “metallizing” quantum magnets. This project will take a unique approach by using strategical materials design to address these two obstacles. The project also will support the education and activities of two graduate students. The principal investigator’s educational effort is to attract undergraduate and high school students to the real world of science and technology and to motivate them to pursue careers in science by bridging the gap between research and educational settings. The main activities include: (i) bringing the lab to the classroom by integrating the exposure to the PI’s research program and research facility into existing undergraduate courses; (ii) bringing the classroom to the lab by developing a summer seminar; (iii) reach out to high school students through the Governor Summer School of the Tennessee state.Technical Abstract:This project will focus on triple perovskites A3BC2O9, in which the effective spin-1/2 magnetic ions form a two-dimensional equilateral triangular lattice. Therefore, this system fits all the requirements for maximized QSFs. The chemical substitution on A sites or C sites can easily introduce perturbations, such as anisotropy and quenched disorder into the system. Moreover, the PI also can use its “sandwich” structure, by combining high pressure, to explore the metallization of quantum magnets. The approach includes (i) crystal growth of the new triple perovskites; (ii) studies on how the QSFs react to the perturbations and how the physical properties of the sandwich structure involve under high pressure by complementary low temperature, high magnetic field, and high pressure measurements, including AC susceptibility, specific heat, thermal conductivity, resistivity, elastic and inelastic neutron scattering, and total scattering for pair distribution function (PDF). The expected outcomes will provide (i) new QSL candidates and guidelines for new QSL search; (ii) a new direction for metallizing quantum magnets and fundamental knowledge about how the itinerant electrons interact with quantum spin states.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：虽然量子计算机的崛起有朝一日可能有助于解决复杂的问题并以不可破解的安全性传递信息，但缺乏可扩展实现量子技术的物质平台。例如，著名的量子自旋液体(QSL)最有趣的磁性是量子力学加密和信息传输的可能性，不受环境影响。尽管对QSL进行了广泛的研究，但它们离应用还很远。第一个障碍是对这一新阶段物质的认识不足。人们普遍认为，强量子自旋涨落(QSFs)在QSLs中起着关键作用，但QSFs究竟如何导致QSL态或其他奇异的量子磁现象尚不清楚。第二个障碍是，大多数研究的QSL是绝缘体和电子惰性的，这与依赖移动电荷载流子的电路不兼容。最大的挑战是找到一种方法，通过对量子磁铁进行金属化，将纠缠信息转换为移动电荷信号。这个项目将采取一种独特的方法，使用战略性材料设计来解决这两个障碍。该项目还将支持两名研究生的教育和活动。首席研究人员的教育努力是通过弥合研究和教育环境之间的差距，吸引本科生和高中生进入现实的科学技术世界，并激励他们追求科学事业。主要活动包括：(I)通过将与PI的研究计划和研究设施的接触整合到现有的本科课程中，将实验室带到课堂上；(Ii)通过开发暑期研讨会将课堂带到实验室；(Iii)通过田纳西州州长暑期学校接触到高中生。技术摘要：该项目将专注于三重钙钛矿A3BC2O9，其中有效的自旋1/2磁离子形成一个二维等边三角形晶格。因此，该系统符合最大化QSFs的所有要求。A位或C位上的化学取代极易引起微扰，如各向异性和猝灭无序等。此外，PI还可以利用其三明治结构，通过结合高压来探索量子磁铁的金属化。该方法包括(I)新的三重钙钛矿结构的晶体生长；(Ii)通过互补的低温、强磁场和高压测量来研究准三元结构对微扰的反应以及夹层结构的物理性质如何涉及高压，包括交流磁化率、比热、热导率、电阻率、弹性和非弹性中子散射以及对分布函数的总散射(PDF)。预期的结果将提供(I)新的QSL候选者和新的QSL搜索指南；(Ii)金属化量子磁体的新方向和关于巡回电子如何与量子自旋态相互作用的基础知识。这一奖项反映了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。

项目成果

Neutron scattering investigation of proposed Kosterlitz-Thouless transitions in the triangular-lattice Ising antiferromagnet TmMgGaO4

• DOI: 10.1103/physrevb.103.064424
• 发表时间: 2020-11
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Z. Dun;Marcus Daum;R. Baral;H. Fischer;H. Cao;Yaohua Liu;M. Stone;J. Rodriguez-Rivera;E. Choi;Qing Huang;Haidong Zhou;M. Mourigal;B. Frandsen

Spin-orbit coupling controlled ground states in the double perovskite iridates A2BIrO6 ( A= Ba, Sr; B= Lu, Sc)

双钙钛矿虹彩 A2BIrO6 中自旋轨道耦合控制的基态 (A= Ba, Sr; B= Lu, Sc)

• DOI: 10.1103/physrevmaterials.6.094409
• 发表时间: 2022
• 期刊: Physical Review Materials
• 影响因子: 3.4
• 作者: Aczel, A. A.;Chen, Q.;Clancy, J. P.;dela Cruz, C.;Reig-i-Plessis, D.;MacDougall, G. J.;Pollock, C. J.;Upton, M. H.;Williams, T. J.;LaManna, N.
• 通讯作者: LaManna, N.

High-field magnetic structure of the triangular antiferromagnet RbFe(MoO4)2

三角形反铁磁体RbFe(MoO4)2的高场磁结构

• DOI: 10.1103/physrevb.105.014431
• 发表时间: 2022
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Sakhratov, Yu. A.;Prokhnenko, O.;Shapiro, A. Ya.;Zhou, H. D.;Svistov, L. E.;Reyes, A. P.;Petrenko, O. A.
• 通讯作者: Petrenko, O. A.

The Transport Properties of Quasi–One-Dimensional Ba3Co2O6(CO3)0.7

• DOI: 10.3389/fphy.2021.785801
• 发表时间: 2021-12
• 作者: Minna Chen;Jiangtao Wu;Qing Huang;J. Jiao;Z. Dun;Guohua Wang;Zhiwei Chen;G. Lin;Vasudevan Ra

Non-magnetic ion site disorder effects on the quantum magnetism of a spin-1/2 equilateral triangular lattice antiferromagnet

• DOI: 10.1088/1361-648x/ac5703
• 发表时间: 2022-05-18
• 期刊: JOURNAL OF PHYSICS-CONDENSED MATTER
• 影响因子: 2.7
• 作者: Huang，Q.;Rawl，R.;Zhou，H. D.
• 通讯作者: Zhou，H. D.