Nematic Enhancement of Superconductivity

超导性的向列增强

• 批准号: 1905891
• 负责人: Johnpierre Paglione
• 金额: $ 45万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1905891&HistoricalAwards=false
• 关键词: Nematic; Enhancement; Superconductivity

Nontechnical abstract:Nematicity, which has been a central theme in the study of iron-based superconductors, is a term borrowed from the field of liquid crystals, where it refers to a phase with broken rotational but preserved translational symmetry. High temperature superconductivity in copper-oxide and iron-pnictide materials continues to fascinate and stimulate the scientific community due to the unanswered questions about the mechanism behind Cooper pairing of electrons to produce record-high transition temperatures. These factors demand not only continued investigation and characterization of known nematic systems but an additional, targeted research effort to uncover and understand other nematic systems and its potential applications within material physics. However, understanding electronic nematicity, and its impact on superconductivity, is limited by the dearth of materials demonstrated to exhibit an electronic nematic phase. These materials are mostly limited to certain high-Tc superconductors and a small handful of other complex materials. In this project, a series of experiments probing both the nematic response and the superconducting state properties of nematically active materials are performed to help understand the influence of nematic fluctuations on superconductivity, and hence elucidate the role of nematicity in enhancing transition temperatures in both iron- and copper-based high-Tc superconductors. This project involves undergraduate, graduate and postdoctoral scientists in interdisciplinary research and areas of scientific and technological significance, including collaborative and exchange programs with external institutions, and includes participation in the Graduate Resources Advancing Diversity with Maryland Astronomy and Physics (GRADMAP) program, the Fundamentals of Quantum Materials Winter School, and the NIST Summer Undergraduate Research Fellowships (SURF) Program.Technical abstract:Electronically driven nematicity has taken on an increased significance as a widely observed phase in the larger electronic phase diagrams of both copper- and iron-based high-temperature superconductor systems. As a generic feature of many iron and cuprate superconductors, understanding electronic nematicity, particularly as it relates to these specific compounds, is essential to truly understanding the conditions from which high Tc emerges. However, in these systems other complicating factors, commonly long range magnetic order, make the impacts of the nematic phase challenging to isolate. This project investigates the BaNi2As2 nickel-pnictide system, a newly discovered nematically enhanced superconductor series that is free of magnetism. Transport and thermodynamic measurements as well as scattering experiments are being employed to characterize both the electronic nematic properties as well as the nature of the superconducting state as the electronic system is tuned by chemical pressure, doping and applied strain. With a growing body of theoretical work suggesting that nematicity may in fact interact cooperatively with Cooper pairing, understanding this correlated electronic phase and how it relates to pairing is thus crucial to understanding and advancing high-Tc superconductivity.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：向列性一直是铁基超导体研究的中心主题，是一个借用自液晶领域的术语，指的是旋转对称性被破坏但保留平移对称性的相。 由于关于电子库珀配对产生创纪录的高转变温度背后的机制的问题尚未得到解答，氧化铜和铁磷化物材料的高温超导性继续吸引和刺激科学界。这些因素不仅需要对已知向列系统进行持续的研究和表征，还需要额外的、有针对性的研究工作来发现和理解其他向列系统及其在材料物理学中的潜在应用。然而，由于缺乏证明具有电子向列相的材料，对电子向列相及其对超导性的影响的理解受到限制。这些材料主要限于某些高温超导体和少数其他复杂材料。在该项目中，进行了一系列实验，探讨向列活性材料的向列响应和超导态特性，以帮助了解向列涨落对超导性的影响，从而阐明向列性在提高铁和超导材料的转变温度方面的作用。和铜基高温超导体。该项目涉及跨学科研究和具有科学技术意义的领域的本科生、研究生和博士后科学家，包括与外部机构的合作和交流项目，并包括参与马里兰州天文学和物理学研究生资源促进多样性（GRADMAP）计划、基础知识量子材料冬季学校和 NIST 夏季本科生研究奖学金 (SURF) 计划。技术摘要：电子驱动向列相作为较大电子中广泛观察到的相，具有越来越重要的意义铜基和铁基高温超导体系统的相图。作为许多铁和铜酸盐超导体的一般特征，了解电子向列性，特别是与这些特定化合物相关的电子向列性，对于真正了解高 Tc 出现的条件至关重要。然而，在这些系统中，其他复杂因素（通常是长程磁序）使得向列相的影响难以隔离。该项目研究 BaNi2As2 镍磷化物系统，这是一种新发现的无磁性向列增强超导体系列。当电子系统通过化学压力、掺杂和施加的应变进行调节时，输运和热力学测量以及散射实验被用来表征电子向列特性以及超导态的性质。随着越来越多的理论工作表明向列性实际上可能与库珀配对相互作用，了解这种相关电子相及其与配对的关系对于理解和推进高温超导性至关重要。该奖项反映了 NSF 的法定使命，并具有通过使用基金会的智力优点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

Absence of precursor incommensurate charge order in electronic nematic Ba0.35Sr0.65Ni2As2

电子向列相 Ba0.35Sr0.65Ni2As2 中不存在前体不相称的电荷顺序

• DOI: 10.1103/physrevb.106.054107
• 发表时间: 2022
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Collini, John;Lee, Sangjun;Sun, Stella X.-L.;Eckberg, Chris;Campbell, Daniel J.;Abbamonte, Peter;Paglione, Johnpierre
• 通讯作者: Paglione, Johnpierre

Sixfold enhancement of superconductivity in a tunable electronic nematic system

• DOI: 10.1038/s41567-019-0736-9
• 发表时间: 2020
• 期刊: Nature physics
• 影响因子: 19.6
• 作者: Eckberg C;Campbell DJ;Metz T;Collini J;Hodovanets H;Drye T;Zavalij P;Christensen MH;Fernandes RM;Lee S;Abbamonte P;Lynn JW;Paglione J
• 通讯作者: Paglione J

Pressure-induced suppression of ferromagnetism in the itinerant ferromagnet LaCrSb3

压力诱导的巡回铁磁体 LaCrSb3 中铁磁性的抑制

• DOI: 10.1103/physrevb.101.214408
• 发表时间: 2020
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Brubaker, Z. E.;Harvey, J. S.;Badger, J. R.;Ullah, R. R.;Campbell, D. J.;Xiao, Y.;Chow, P.;Kenney-Benson, C.;Smith, J. S.;Reynolds, C.
• 通讯作者: Reynolds, C.