Magnetic Properties of Quasi-One Dimensional Molecular Conductors

准一维分子导体的磁性

• 批准号: 9701597
• 负责人: Michael Naughton
• 金额: $ 9.95万
• 依托单位: SUNY at Buffalo
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-15 至 1998-08-26
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9701597&HistoricalAwards=false
• 关键词: Magnetic; Properties; Quasi; Dimensional; Molecular

97-01597 Naughton This is a renewal proposal to study superconducting, metallic and dielectric properties of the quasi-one dimensional molecular conductors TMTSF at low temperatures and large magnetic fields. Recent transport studies to B=7T of the upper critical field Phys. Rev. Lett. 78, 3555 (1997) provide strong evidence for unconventional spin-triplet pairing, and a novel field- induced dimensional crossover. These and similar magnetic measurements will be extended to higher fields in a search for reentrant superconductivity which has been predicted for such quasi-1- d superconductors. In the normal state, the origin of a new series of angular magnetoresistance oscillations, which map the curvature of the Fermi surface, will be investigated. A search for corresponding angular magnetic oscillations via torque magnetometry will be initiated. In the dielectric state, the origin of the "fast oscillations" will be investigated via torque and transport in pulsed fields to 100T. %%% This is a renewal proposal to study superconducting, metallic and dielectric properties of the quasi-one dimensional molecular conductors TMTSF at low temperatures and large magnetic fields Superconductivity arises when two negatively charged electrons become attracted to each other and become "paired", in spite of the fact that "opposites attract while likes repel". In all conventional superconductors, these paired electrons have opposite spin, such that the total spin of the pair is zero, a fact which plays an important role in the explanation of the superconducting state. A recent theory has predicted, however, that in certain materials in which electrons are confined to move mostly in one direction, electrons with the same, rather than opposite, spin, can form pairs, and superconduct. One consequence of this pairing would be that a magnetic field could enhance, rather than destroy , the superconducting state, opening the interesting possibility of superconductivity reappearing in very high magnetic fields. This project involves a search for high field superconductivity in a one- dimensional molecular conductor, where initial studies are strongly suggestive of equal spin pairing and reentrant superconductivity. ***

97-01597 Naughton这是研究准一维分子导体TMTSF在低温和大磁场下的超导、金属和介电性质的更新建议。 最近的输运研究B= 7 T的上临界场物理评论Lett。78，3555（1997）提供了非常规自旋-三重态配对的强有力证据，以及一种新的场诱导的 维 交叉。 这些 和 类似 磁测量将被扩展到更高的场，以寻找已被预测用于这种准一维超导体的可重入超导性。 在正常状态下，一系列新的角磁阻振荡的起源，映射的费米表面的曲率，将被调查。 搜索相应的角度 通过转矩磁力测量法的磁振荡将 被启动。 在介电状态下， “快速振荡”将通过扭矩和100 T脉冲场中的传输进行研究。 这是研究准一维分子导体TMTSF在低温和大磁场下的超导、金属和介电性质的一个新的建议。当两个带负电荷的电子相互吸引并成为“配对”时，尽管存在“异性相吸，异性相斥”的事实，超导性就产生了。 在所有传统的超导体中，这些成对的电子具有相反的自旋，使得该对的总自旋为零，这一事实在解释超导状态中起着重要作用。 然而，最近的一个理论预测，在某些材料中，电子被限制在一个方向上运动，具有相同而不是相反的自旋的电子可以形成对，并且超导。 这种配对的一个结果是，磁场可以增强而不是破坏超导体。 国家，打开有趣的 可能性 超导性在极强磁场中重现的证据。 这个计画涉及在一维分子导体中寻找高场超导性，其中初步研究强烈暗示相等自旋配对和重入超导性。 ***