期刊
PHYSICAL REVIEW B
卷 97, 期 1, 页码 -出版社
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevB.97.014530
关键词
-
资金
- German Research Foundation (Deutsche Forschungsgemeinschaft) [SFB/TR 49]
Starting from an ab initio-derived two-site dimer Hubbard Hamiltonian on a triangular lattice, we calculate the superconducting gap functions and critical temperatures for representative kappa-(BEDT-TTF)(2)X superconductors by solving the linearized Eliashberg equation using the two-particle self-consistent approach (TPSC) extended to multisite problems. Such an extension allows for the inclusion of molecule degrees of freedom in the description of these systems. We present both benchmarking results for the half-filled dimer model as well as detailed investigations for the 3/4-filled molecule model. Remarkably, we find in the latter model that the phase boundary between the two most competing gap symmetries discussed in the context of these materials-d(xy) and the recently proposed eight-node s + dx(2)-y(2) gap symmetry-is located within the regime of realistic model parameters and is especially sensitive to the degree of in-plane anisotropy in the materials as well as to the value of the on-site Hubbard repulsion. We show that these results provide a more complete and accurate description of the superconducting properties of kappa-(BEDT-TTF)(2)X than previous random phase approximation (RPA) calculations and, in particular, we discuss predicted critical temperatures in comparison to experiments. Finally, our findings suggest that it may be even easier to experimentally switch between the two pairing symmetries as previously anticipated by invoking pressure, chemical doping, or disorder effects.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据