蜂巢晶格材料中的扩展s波超导电性

Extended s-Wave Superconductivity in Materials with Honeycomb Lattice

利用动能驱动的超导电性理论研究了掺杂蜂巢晶格材料的非常规超导电性.结果表明,掺杂蜂巢晶格材料扩展s波对称性的电荷载流子配对能隙参数随掺杂浓度的变化呈圆顶状,说明掺杂蜂巢晶格材料中是可能出现扩展s波超导态的;电荷载流子配对能隙参数随温度的增加而逐渐减小,在超导转变温度处变为零,而超导转变温度随掺杂浓度的变化也呈圆顶状,与实验结果定性一致;动能驱动的超导电性理论同样适用于定性研究具有蜂巢晶格结构的掺杂莫特绝缘体的超导电性.

Superconductivity on a honeycomb lattice has been studied by using the theory of kinetic-energydriven superconductivity.Our theoretical results demonstrate that the doping dependence of the charge-carrier pair gap parameter with extended s-wave symmetry exhibits dome-like shape,which suggests that an extended s-wave superconducting state can possibly emerge in doped honeycomb-lattice materials.In addition,the charge-carrier pair gap parameter decreases gradually with increasing temperature and approaches zero at the superconducting transition temperature.The doping dependence of superconducting transition temperature also exhibits dome-like shape,which is qualitatively in agreement with experimental results.Our results also demonstrate that the theory of kinetic-energy-driven the superconductivity can also be applied to qualitatively study superconductivity of doped Mott insulators with honeycomb lattice.