耦合量子点中空穴基态反键态特性研究  

Bonding-antibonding ground state transition in coupled quantum dots

作　　者：汤乃云[1] 

机构地区：[1]上海电力学院电子科学与技术系,上海200090

出　　处：《物理学报》2013年第5期393-397,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61204105);上海自然科学基金(批准号:B10ZR1412400);上海市科技创新行动计划地方院校能力建设项目(批准号:10110502200)资助的课题~~

摘　　要：本文采用六带K·P理论计算了耦合量子点在不同耦合距离下空穴基态特性,探讨了轻重空穴及轨道自旋相互作用对耦合量子点空穴基态反成键态特性的影响.在考虑多带耦合的情况下,耦合量子点随着耦合强度的变化,价带基态能级和激发态能级发生反交叉现象.同时,随着耦合距离的增加,量子点基态轻重空穴波函数的比重发生变化,导致量子点空穴基态波函数从成键态反转成为反成键态.同时研究发现,因空穴基态及激发态波函数特性的转变,电子、空穴的基态及激发态波函数的叠加强度发生的明显变化.The two lowest single-particle hole states in two vertically coupled quntum dots （CQDs） are investigated by using the six-band K - P model. A bondJng-antibonding ground-state transition is observed with interdot distance increasing. This result is counterintuitive, for the antibonding molecular ground state has never been observed in natural diatomic molecules. By comparing the wavafunction component of hole, we verify that the reordering of bonding and antibonding orbitals with interdot distance increasing is caused by spin-orbit interaction of holes.

关 键 词：耦合量子点 反键态 多带理论 自旋轨道耦合 

分 类 号：O471.1[理学—半导体物理]