Microscopic observation of superconducting fluctuations in κ-(BEDT-TTF)2Cu[N(CN)2]Br by 13C NMR spectroscopy

被引：10

作者：

Kobayashi, T. ^{[1
]}

Ihara, Y. ^{[1
]}

Saito, Y. ^{[1
]}

Kawamoto, A. ^{[1
]}

机构：

[1] Hokkaido Univ, Grad Sch Sci, Dept Condensed Matter Phys, Sapporo, Hokkaido 0600810, Japan

来源：

PHYSICAL REVIEW B | 2014年 / 89卷 / 16期

关键词：

MIXED-STATE; RELAXATION;

D O I：

10.1103/PhysRevB.89.165141

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We performed C-13-NMR experiment and measured spin-lattice relaxation rate divided by temperature 1/T1T near the superconducting (SC) transition temperature T-c in kappa-(BEDT-TTF)(2)Cu[N(CN)(2)] Br (kappa-Br salt), and kappa-(BEDT-TTF)(2)Cu(NCS)(2) (kappa-NCS salt). We observed the reduction of 1/T1T starting at the temperature higher than T-c in kappa-Br salt. Microscopic observation of the quasiparticle density of states in the fluctuating SC state revealed the effects of short-range Cooper pairs induced in the normal state to the quasiparticle density of states. We also performed systematic measurements in the fields both parallel and perpendicular to the conduction plane in kappa-Br and kappa-NCS salts, and confirmed that the reduction of 1/T1T above T-c is observed only in kappa-Br salt regardless of the external field orientation.

引用

页数：5

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