并联双量子点体系中的RKKY相互作用及局域磁矩  

RKKY Interaction and Local Magnetic Moment for a Parallel Double Dot System

作　　者：熊永臣 罗时军[1] 杨俊涛[1] 

机构地区：[1]湖北汽车工业学院理学院,湖北十堰442002

出　　处：《湖北汽车工业学院学报》2015年第4期59-61,80,共4页Journal of Hubei University Of Automotive Technology

基　　金：湖北省自然科学基金(2015CFC789);湖北汽车工业学院重大科研项目预研基金(2014XY06);湖北汽车工业学院博士基金(BK201407)

摘　　要：借助数值重整化群方法研究了并联双量子点体系中,在位库伦排斥作用及温度对体系局域态密度及磁矩的影响。计算表明:态密度中观察到的RKKY相互作用与在位库伦作用成反比关系;随着温度的变化,局域磁矩依次经历自由轨道区间、局域磁矩区间、自旋三重态区间以及Kondo屏蔽区间。计算结果和微扰理论的结果是吻合的。相关结论可以用来描述半导体量子点器件、磁性杂质、磁性分子结及相关团簇吸附问题的强关联效应。The effects of the on-site Coulomb repulsion and temperature on the local density of states（DOS） and magnetic moment in a parallel double quantum dot system were studied by means of the nu-merical renormalization group method. The results show that the Ruderman–Kittel–Kasuya–Yosida（RKKY） interaction identified in the DOS is inversely proportional to U, and as temperature decreases,the magnetic moment goes through the following regimes： free orbital regime, local moment regime, spintriplet regime and Kondo screened regime. The numerical results are consistent with the perturbationtheory. The results can be used to describe the strongly correlated effects of semiconductor quantum dotdevices, magnetic impurities embedded in a metallic host, magnetic molecular junction and clusters onmetallic surfaces.

关 键 词：双量子点体系 RKKY相互作用 数值重整化群 强关联体系 KONDO效应 

分 类 号：O469[理学—凝聚态物理]