Exotic superconductivity in strongly anisotropic correlatedorganic metals in the vicinity of insulating phases

绝缘相附近强各向异性相关有机金属的奇异超导性

• 批准号: 234757034
• 负责人: Dr. Mark Kartsovnik
• 金额: --
• 依托单位: Federal Research Centre of Problems of Chemical Physics and Medicinal Chemistry
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/234757034?language=en
• 关键词: Exotic; superconductivity; strongly; anisotropic; correlatedorganic

Unconventional superconductivity with the order parameter oscillating in momentum or real space, which is expected to be realized in conducting materials with strong electronic correlations, has lately been a subject of great interest. Organic metals possess a number of features, which make them particularly attractive model systems for systematically studying the subtle interplay between superconductivity and other instabilities of the normal metallic state.The main goal of this project is to reveal manifestations of exotic superconductivity and its interplay with other ordering instabilities in these materials. The compounds chosen for studies exhibit superconductivity in the immediate vicinity to and even coexisting with other ordered ground states: the charge-density-wave metal alpha-(ET)2KHg(SCN)4; the antiferromagnetic metal kappa-(BETS)2FeCl4; the magnetically ordered (probably Mott) insulator kappa-(BETS)2Mn[N(CN)2]3. The project aims at clarifying the influence of the competing orderings on superconducting (SC) properties of these compounds. The relative strength of the ordering instabilities in all these compounds is sensitive to pressure. This provides a convenient opportunity for studying the dependence of SC properties on the pressure-controlled proximity to the density-wave or magnetic ordering.Due to the very high electronic anisotropy, the orbital pair-breaking effect of a magnetic field parallel to layers is strongly suppressed in these materials. In this situation the Pauli paramagnetic effect on charge carriers is expected to be the dominant pair-breaking mechanism. If the samples are clean enough, this will provide the necessary and sufficient condition for a field-induced transition from a homogeneous SC state into the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state with an order parameter oscillating in real space. The search for the FFLO state in the above mentioned compounds is another major objective of this project.Two of the chosen compounds are characterized by very low SC critical temperatures (about 0.1K). This facilitates straightforward measurements of the critical fields since the vortex dynamics effects in transport and magnetization, which usually cause big problems in quasi-two-dimensional superconductors, are strongly suppressed in the whole SC range. The research project is planned in cooperation with partners at Chernogolovka, Russia, who will deliver the crystals for the physical investigations and develop novel materials which will also be tested within the project. The experiments on kappa-(BETS)2Mn[N(CN)2]3 will also be conducted in cooperation with the Russian partners.

在动量或真实空间中振荡的顺序参数的非常规超导性，预计在执行具有较强电子相关性的材料中可以实现，这是一个引起极大兴趣的主题。有机金属具有许多特征，这使它们成为系统地研究超导性和正常金属状态的其他不稳定性之间的微妙相互作用的特别有吸引力的模型系统。该项目的主要目标是揭示外来超导性的表现及其与这些材料中其他订购不可限制的相互作用的表现。选择用于研究的化合物在附近甚至与其他有序基态共存的超导性：电荷密度金属α-（ET）2KHG（SCN）4;抗铁磁金属kappa-（BETS）2FECL4;磁有序（可能是Mott）绝缘子Kappa-（BETS）2MN [N（CN）2] 3。该项目旨在阐明竞争秩序对这些化合物超导（SC）特性的影响。所有这些化合物中有序不稳定性的相对强度对压力敏感。这为研究SC特性的依赖性提供了一个方便的机会，对与密度波或磁性有序的压力控制接近性。到了非常高的电子各向异性，在这些材料中，与层平行的磁场的轨道配对效应相似。在这种情况下，Pauli顺磁性对电荷载体的影响预计将是主要的成对机制。如果样品足够干净，这将为从均匀的SC状态过渡到fulde-ferrell-larkin-ovchinnikov（FFLO）状态，以提供必要的条件，并具有在实际空间中振荡的顺序参数。在上述化合物中搜索FFLO状态是该项目的另一个主要目标。所选化合物的两个特征是SC临界温度非常低（约0.1K）。这有助于对临界场的直接测量，因为在整个SC范围内，涡流动力学在运输和磁化方面的涡流动力学效应通常在准二维超导体中引起很大问题。该研究项目计划与俄罗斯切尔诺戈洛洛夫卡的合作伙伴合作，该公司将为物理调查提供水晶，并开发新的材料，这些材料也将在该项目中进行测试。关于Kappa-（BETS）2MN [N（CN）2] 3的实验也将与俄罗斯合作伙伴合作进行。

项目成果

Magnetic quantum oscillations in the charge-density-wave state of the organic metals α-(BEDT-TTF)2MHg(SCN)4 with M = K and Tl

有机金属 α-(BEDT-TTF)2MHg(SCN)4 的电荷密度波状态下的磁量子振荡，其中 M = K 和 Tl

• DOI: 10.1063/1.4869592
• 发表时间: 2014
• 期刊: Low Temperature Physics
• 影响因子: 0.8
• 作者: M. V. Kartsovnik;V. N. Zverev;D. Andres;W. Biberacher;T. Helm;P. D. Grigoriev;R. Ramazashvili;N. D. Kushch;H. Mü ller
• 通讯作者: H. Mü ller

New radical cation salt κ-(BETS)2Co0.13Mn0.87[N(CN)2]3 with two magnetic metals: Synthesis, structure, conductivity and magnetic peculiarities

具有两种磁性金属的新型自由基阳离子盐 γ-(BETS)2Co0 13Mn0 87[N(CN)2]3：合成、结构、电导率和磁性特性

• DOI: 10.1016/j.synthmet.2017.03.008
• 发表时间: 2017
• 期刊: Synthetic Metals
• 影响因子: 4.4
• 作者: N. D. Kushch;O. M. Vyaselev;V. N. Zverev;W. Biberacher;L. I. Buravov;E. B. Yagubskii;E. Herdtweck;E. Canadell;M. V. Kartsovnik
• 通讯作者: M. V. Kartsovnik

Interplay Between Conducting and Magnetic Systems in the Antiferromagnetic Organic Superconductor κ-(BETS)2FeBr4

反铁磁有机超导体 γ-(BETS)2FeBr4 中传导系统和磁系统之间的相互作用

• DOI: 10.1007/s10948-016-3829-z
• 发表时间: 2016
• 期刊: Journal of Superconductivity and Novel Magnetism
• 影响因子: 1.8
• 作者: M. V. Kartsovnik;M. Kunz;L. Schaidhammer;F. Kollmannsberger;W. Biberacher;N. D. Kushch;A. Miyazaki;H. Fujiwara
• 通讯作者: H. Fujiwara

Resistive properties and phase diagram of the organic antiferromagnetic metal κ -(BETS ) 2 FeCl 4

有机反铁磁金属γ -(BETS ) 2 FeCl 4 的电阻特性及相图

• DOI: 10.1103/physrevb.94.205104
• 发表时间: 2016
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: M. Kunz;W. Biberacher;N.D. Kushch;A. Miyazaki;M. V. Kartsovnik
• 通讯作者: M. V. Kartsovnik

Interplay between the d - and π -electron systems in magnetic torque of the layered organic conductor κ -(BETS) 2 Mn [N (CN )2 ] 3

层状有机导体磁矩中 d 电子系统和 Ï 电子系统之间的相互作用 γ -(BETS) 2 Mn [N (CN )2 ] 3

• DOI: 10.1103/physrevb.96.205154
• 发表时间: 2017
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: O. M. Vyaselev;W. Biberacher;N. D. Kushch;M. V. Kartsovnik
• 通讯作者: M. V. Kartsovnik