Origin of the Superconductivity in \beta'-(BEDT-TTF)_2ICl_2 under High Pressure and \beta-(BEDT-TTF)_2X at Ambient Pressure
Origin of the Superconductivity in \beta'-(BEDT-TTF)_2ICl_2 under High Pressure and \beta-(BEDT-TTF)_2X at Ambient Pressure
复制标题
高压下 β-(BEDT-TTF)_2ICl_2 和常压下 β-(BEDT-TTF)_2X 超导性的起源
DOI：
10.1103/physrevb.67.180503
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发表时间：
2003
影响因子：
3.7
通讯作者：
H. Kontani
中科院分区：
文献类型：
--
作者：
H. Kontani
本文对谷口等人发现的β ′-（BEDT-TTF）_2ICl_2在T_c =14.2K高压下的超导电性进行了理论研究。这是有机超导体中的最高记录。其电子结构可用各向异性三角晶格Hubbard模型描述。在目前的工作中，我们研究这个有效的模型，使用波动交换（FLEX）近似。在所得到的相图中，由于压力驱动的一维-二维空间交叉，在反铁磁（AF）绝缘相附近实现了类d_{x^2-y^2}对称的超导电性。测得的最大Tc为16- 18 K。此外，β-（BEDT-TTF）_2X中的超导电性也在同一框架下得到了理解。
We present a theoretical study on the superconductivity in \beta'-(BEDT-TTF)_2ICl_2 at Tc=14.2K under high hydrostatic pressure found by Taniguchi et al., which is the highest record among organic superconductors. Its electronic structure is well expressed by the anisotropic triangular lattice Hubbard model at half filling. In the present work, we study this effective model by using the fluctuation-exchange (FLEX) approximation. In the obtained phase diagram, the superconductivity with d_{x^2-y^2} like symmetry is realized next to the antiferromagnetic (AF) insulating phase, as a result of the 1D-2D dimensional crossover driven by the pressure. The obtained maximum Tc is 16-18K. In addition, the superconductivity in \beta-(BEDT-TTF)_2X is also understood in the same framework.