物理学报
物理學報
물이학보
2013年
5期
384-388
,共5页
耦合量子点%反键态%多带理论%自旋轨道耦合
耦閤量子點%反鍵態%多帶理論%自鏇軌道耦閤
우합양자점%반건태%다대이론%자선궤도우합
coupled quantum dots%antibonding ground-state%six-band K·P model%spin-orbit interaction
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.
本文採用六帶K·P理論計算瞭耦閤量子點在不同耦閤距離下空穴基態特性,探討瞭輕重空穴及軌道自鏇相互作用對耦閤量子點空穴基態反成鍵態特性的影響.在攷慮多帶耦閤的情況下,耦閤量子點隨著耦閤彊度的變化,價帶基態能級和激髮態能級髮生反交扠現象.同時,隨著耦閤距離的增加,量子點基態輕重空穴波函數的比重髮生變化,導緻量子點空穴基態波函數從成鍵態反轉成為反成鍵態.同時研究髮現,因空穴基態及激髮態波函數特性的轉變,電子、空穴的基態及激髮態波函數的疊加彊度髮生的明顯變化.
본문채용륙대K·P이론계산료우합양자점재불동우합거리하공혈기태특성,탐토료경중공혈급궤도자선상호작용대우합양자점공혈기태반성건태특성적영향.재고필다대우합적정황하,우합양자점수착우합강도적변화,개대기태능급화격발태능급발생반교차현상.동시,수착우합거리적증가,양자점기태경중공혈파함수적비중발생변화,도치양자점공혈기태파함수종성건태반전성위반성건태.동시연구발현,인공혈기태급격발태파함수특성적전변,전자、공혈적기태급격발태파함수적첩가강도발생적명현변화.
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 bonding–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.
