Probing Exotic Phases of Ultra High Mobility Two-Dimensional Electrons

探测超高迁移率二维电子的奇异相

• 批准号: 2104771
• 负责人: Mansour Shayegan
• 金额: $ 68万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2104771&HistoricalAwards=false
• 关键词: Probing; Exotic; Phases; Ultra; Mobility

Non-technical Description:A major research area in solid-state science and engineering is the study of how the electrons in a solid interact. The interaction stems from the repulsion between electrons because of their electric charge, as well as their spin and other degrees of freedom. It leads to exotic, often unexpected, phases of matter. To study these phases and phenomena, it is important to minimize the imperfections, such as impurities and defects, so that electron-electron interaction is the dominating factor. The goal of this project is to experimentally explore and understand the new phases that arise in electron systems with the least amount of imperfections. Results of the research are communicated through publications and conference presentations to the specialized as well as general science and engineering communities. While the subject of this project is fundamental, progress in this area benefits society in the long term as it may lead to novel, transformative concepts for electronic devices and information processing systems, such as a quantum computer, whose operation relies on quantum and/or interaction phenomena. The project also incorporates a high quality and comprehensive educational component as it includes the education of students in critical, state-of-the art areas of science and technology, including the fabrication, characterization, and physics of very high-quality, thin-film semiconductor structures. Well-trained students in these fields are invaluable resources for the US as well as for the rest of the world. Technical Description:This project encompasses experimental investigations of electron interaction physics in quantum-confined GaAs/AlGaAs semiconductor structures with ultra-high-quality, as quantified by their record-high mobilities and new many-body states. The program includes studies of both fabrication via the molecular beam epitaxy technique, and of the electronic transport properties at low temperatures and high magnetic fields where electron correlation phenomena dominate. The emphasis of the work is on two-dimensional electron and hole systems confined to selectively doped GaAs quantum wells. The two-dimensional electron systems have the highest mobility among all solid-state materials, while the larger effective mass and the strong spin-orbit interaction in two-dimensional hole systems add additional, novel twists to their electronic properties. Several exotic phases of these interacting two-dimensional carrier systems are studied during the course of this project; these include the fractional quantum Hall effect, composite fermions, Wigner crystal, and stripe and bubble phases. Competition between the fractional quantum liquid and the Wigner crystal at large perpendicular magnetic fields (small Landau level filling factors), as well as many-body states in excited Landau levels are being investigated.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.

非技术描述：固体科学和工程的一个主要研究领域是研究固体中的电子如何相互作用。这种相互作用源于电子之间的排斥，因为它们的电荷，以及它们的自旋和其他自由度。它导致了奇异的，经常是意想不到的，物质的相位。为了研究这些相和现象，重要的是要尽量减少不完美，如杂质和缺陷，使电子-电子相互作用是主导因素。该项目的目标是通过实验探索和理解电子系统中出现的新阶段，这些阶段具有最少的缺陷。研究结果通过出版物和会议报告传达给专业和一般的科学和工程界。虽然该项目的主题是基础性的，但从长远来看，这一领域的进展对社会有益，因为它可能为电子设备和信息处理系统带来新的变革性概念，例如量子计算机，其操作依赖于量子和/或相互作用现象。该项目还包括一个高质量和全面的教育组成部分，因为它包括学生在关键的，国家的最先进的科学和技术领域的教育，包括非常高质量的薄膜半导体结构的制造，表征和物理。在这些领域训练有素的学生是美国和世界其他地区的宝贵资源。技术说明：该项目包括量子限制GaAs/AlGaAs半导体结构中电子相互作用物理的实验研究，这些结构具有超高质量，通过其创纪录的高迁移率和新的多体状态进行量化。该计划包括通过分子束外延技术制造的研究，以及在电子相关现象占主导地位的低温和高磁场下的电子输运性质。工作的重点是二维电子和空穴系统局限于选择性掺杂GaAs量子威尔斯。二维电子系统在所有固态材料中具有最高的迁移率，而二维空穴系统中更大的有效质量和强的自旋轨道相互作用为其电子性质增加了额外的新颖扭曲。在这个项目的过程中，这些相互作用的二维载体系统的几个奇异的阶段进行了研究，这些包括分数量子霍尔效应，复合费米子，维格纳晶体，条纹和气泡相。分数量子液体和维格纳晶体之间的竞争在大的垂直磁场（小朗道水平填充因子），以及多体状态的激发朗道水平正在调查。这个奖项反映了NSF的法定使命，并已被认为是值得的支持，通过评估使用基金会的智力价值和更广泛的影响审查标准。

项目成果

Robust Quantum Hall Ferromagnetism near a Gate-Tuned ν=1 Landau Level Crossing

门调谐 ν=1 Landau 平交道口附近的鲁棒量子霍尔铁磁性

• DOI: 10.1103/physrevlett.129.196801
• 发表时间: 2022
• 期刊: Physical Review Letters
• 影响因子: 8.6
• 作者: Ma, Meng K.;Wang, Chengyu;Chung, Y. J.;Pfeiffer, L. N.;West, K. W.;Baldwin, K. W.;Winkler, R.;Shayegan, M.
• 通讯作者: Shayegan, M.

Spontaneous Valley Polarization of Itinerant Electrons

流动电子的自发谷极化

• DOI: 10.1103/physrevlett.127.116601
• 发表时间: 2021
• 期刊: Physical Review Letters
• 影响因子: 8.6
• 作者: Hossain, Md. S.;Ma, M. K.;Villegas-Rosales, K. A.;Chung, Y. J.;Pfeiffer, L. N.;West, K. W.;Baldwin, K. W.;Shayegan, M.
• 通讯作者: Shayegan, M.

Melting phase diagram of bubble phases in high Landau levels

• DOI: 10.1103/physrevb.104.l121110
• 发表时间: 2021-08
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: K. Villegas Rosales;S. Singh;H. Deng;Y. Chung;L. Pfeiffer;K. West;K. Baldwin;M. Shayegan

Highly Anisotropic Even-Denominator Fractional Quantum Hall State in an Orbitally Coupled Half-Filled Landau Level

轨道耦合半填充朗道能级中的高度各向异性偶分母分数量子霍尔态

• DOI: 10.1103/physrevlett.131.056302
• 发表时间: 2023
• 期刊: Physical Review Letters
• 影响因子: 8.6
• 作者: Wang, Chengyu;Gupta, A.;Chung, Y. J.;Pfeiffer, L. N.;West, K. W.;Baldwin, K. W.;Winkler, R.;Shayegan, M.
• 通讯作者: Shayegan, M.

Fractional quantum Hall valley ferromagnetism in the extreme quantum limit

极端量子极限下的分数量子霍尔谷铁磁性

• DOI: 10.1103/physrevb.106.l201303
• 发表时间: 2022
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Hossain, Md. Shafayat;Ma, Meng K.;Chung, Y. J.;Singh, S. K.;Gupta, A.;West, K. W.;Baldwin, K. W.;Pfeiffer, L. N.;Winkler, R.;Shayegan, M.
• 通讯作者: Shayegan, M.