串联强耦合双量子点的电子全计数统计研究  

Full Counting Statistics of Electron Transport Through Two Coherent Strongly Coupled Quantum Dots

作　　者：张宏伟[1] 薛海斌[2] 

机构地区：[1]忻州师范学院物理电子系,山西忻州034000 [2]太原理工大学物理与光电工程学院,山西太原030024

出　　处：《山西大学学报（自然科学版）》2012年第1期56-62,共7页Journal of Shanxi University(Natural Science Edition)

基　　金：山西省自然科学基金(20090110011);国家自然科学基金(10774094)

摘　　要：基于有效粒子数分辨的量子主方程,研究了电子通过串联强耦合双量子点系统的全计数统计.当系统与源极耦合强度远大于漏极,并且与源极耦合的左量子点能级高于与漏极耦合的右量子点时,即εL>εR,在合适的能级失谐情形下,观察到负微分电导,并且其伴随着超泊松噪声,但超泊松噪声偏压区域比较小;但是当εL<εR时,观察到一个比较大的超泊松噪声偏压区域,并且此噪声特性在大能级失谐情形下依然存在.这些超泊松噪声特性可以定性地归结于快慢输运通道之间的有效竞争.The full counting statistics of electron transport through two coherent strongly coupled quantum dots is studied based on an efficient particle-number-resolved master equation.The negative differential conductance is observed for appropriate values of level detuning when the coupling of the quantum dots system with the incident-electrode is stronger than that with the outgoing-electrode,and the on-site energy of the left quantum dot coupled to incident-electrode is larger than that of the right quantum dot coupled to out-electrode,i.e.,εL>εR,which is accompanied by a super-Poissonian noise but that occurs in a small bias voltage range;whereas for the εL<εR case the super-Poissonian noise can appear in a relatively large bias voltage range,and can still occur in the case of an large detuning of level energies,which is contrary to the εL>εR case.The super-Poissonian noise characteristics can be qualitatively attributed to the effective competition between fast and slow transport channels.

关 键 词：量子点 全计数统计 超泊松噪声 

分 类 号：O413.2[理学—理论物理]