Evolution of coherence and superconductivity in electron-doped cuprates

被引：0

作者：

Blumberg, G. ^{[1
]}

Qazilbash, M. M. ^{[2
]}

Dennis, B. S. ^{[1
]}

Greene, R. L. ^{[2
]}

机构：

[1] Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA

[2] Univ Maryland, Dept Phys, College Pk, MD 20742 USA

来源：

LOW TEMPERATURE PHYSICS, PTS A AND B | 2006年 / 850卷

关键词：

superconductivity; Raman scattering; magnetic field;

D O I：

暂无

中图分类号：

O414.1 [热力学];

学科分类号：

摘要：

The superconducting (SC) phase diagram of the electron-doped cuprates has been explored by Raman spectroscopy as a function of doping x, temperature T, and magnetic field H, The data is consistent with nonmonotonic SC order parameter (OP) of the d-wave form. The persistence of SC coherence peaks in the B-2g channel for all dopings implies that superconductivity is mainly governed by interactions in the vicinity of (+/-pi/2a, +/-pi/2a) regions of the Brillouin zone. Effective upper critical field lines H-c2(*) (T,x) at which the superfluid stiffness vanishes and H-c2(2 Delta) (T,x) at which the SC amplitude is suppressed by field have been determined. The difference between the two quantities suggests the presence of phase fluctuations that increase for x < 0.15. It is found that the field suppresses the magnitude of the SC gap linearly at an anomalously large rate. H-c2(2 Delta) value that is about 10 T for optimally doped samples decreases below a Tesla for overdoped cuprates.

引用

页码：525 / +

页数：2