Novel Thermal Transport Phenomena in Quantum Materials

非技术摘要：电子不仅携带电能，还携带能量。电子的这种性质是研究量子材料的强大探测器。电子与热量一起运动会产生电压或揭示固体中的导热。这些可移动电子在磁场作用下可能会改变运动方向，从而产生横向电压和热导。这些新颖的热输运性质对于探测和探测强关联量子材料的基态是必不可少的。这项研究为研究强关联效应和拓扑之间的相互作用打开了大门，为未来的电子学寻找新的量子相、新的拓扑相和新的多功能提供了可能。该项目还提供了培训本科生和研究生的机会，了解这个量子世界的科学和技术。通过让本科生参与研究，创造机会促进女性和少数族裔在科学和工程职业中的融合，将当地学校的学生带到实验室，并向更广泛的公众传播研究，该团队为公众带来了强关联材料的进展，并培养了人们对量子科学和凝聚态物理领域的兴奋、意识和兴趣。技术摘要：该研究项目旨在利用新的热传输特性来研究强关联材料。作为强关联材料和拓扑量子材料研究领域的桥梁，研究小组将利用热电效应和热霍尔效应来揭示最近观察到的强关联材料新现象的物理起源：(1)近藤绝缘体中的量子振荡；(2)未掺杂和掺杂Mott绝缘体中的大热霍尔效应；(3)量子自旋液体中的奇异热输运；以及(4)Kagome金属的平淡现象。这些方向是凝聚态物理学中长期存在的谜题中令人兴奋的新发展。对于电荷中性准粒子在强相互作用态中的作用，他们有着相同的争论：是什么承载了这些有趣的现象：马格农、声子、博戈利乌博夫准粒子，甚至是马约拉纳激发。研究任务将回答以下问题：(1)近藤绝缘体中磁场驱动的绝缘体-金属-金属相变的本质？(2)Mott绝缘未掺杂铜酸盐中强的霍尔热流信号是什么？(3)Kagome量子自旋液体中的基态激发是费米子还是玻色子？(4)Kagome金属中平带的实验特征是什么？对这些问题的回答最终将提供强关联材料的电磁基态的总体图景。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。

Non-technical Abstract: Electrons carry not only electricity but also energy. This property of electrons is a powerful probe for quantum materials. Moving the electrons with heat generates electrical voltages or reveals thermal conductions in the solids. These mobile electrons may change the moving directions under a magnetic field, leading to transverse electrical voltages and thermal conductions. These novel thermal transport properties are essential to detect and probe the ground state of strongly correlated quantum materials. The research brings the potential to open the door to studying the interplay between strong-correlation effects and topology in the search for new quantum phases, novel topological phases, and new multi-functionalities for future electronics. The project also provides opportunities to train undergraduate and graduate students in the science and technology of this quantum world. By involving undergraduates in research, creating opportunities to promote the integration of women and minorities in careers in science and engineering, bringing local school students to laboratories, and communicating research to the broader public, the team brings the general public the advancements in strongly correlated materials and develops excitement, awareness, and interest in the field of quantum science and condensed matter physics. Technical Abstract: The research project aims to investigate strongly correlated materials using novel thermal transport properties. Bridging the research fields of strongly correlated materials and topological quantum materials, the research team will use the thermoelectric effect and thermal Hall effect to reveal the physical origin of recently observed novel phenomena of strongly correlated materials: (1) quantum oscillations in Kondo insulators; (2) large thermal Hall effects in undoped and doped Mott insulators; (3) exotic thermal transport in quantum spin liquid; and (4) flat-bland phenomena of Kagome metals. These directions are exciting new developments in long-standing puzzles in condensed matter physics. They share the same debate about the role of the charge-neutral quasiparticles in the strongly interacted states: what carries these interesting phenomena: magnon, phonon, Bogoliubov quasiparticles, or even Majorana excitations. The research tasks will answer these questions: (1) What is the nature of the magnetic-field-driven insulator-metal-transition in Kondo insulators? (2) What causes strong Hall signals of the heat current in Mott insulating undoped cuprates? (3) Are the fundamental excitations fermionic or bosonic in Kagome quantum spin liquid? (4) What are the experimental signatures of the flat band in Kagome metals? Answers to these questions will eventually provide the big picture of the electronic and magnetic ground states of strongly correlated materials.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.