摘要
研究磁场作用下与左右两个二维电子气耦合的双量子点系统中的自旋极化输运过程.结果发现当两个量子点靠近时,电导中会出现Dicke效应导致的不对称尖峰.随着量子点间的距离增大,Dicke尖峰变宽并向低能级方向移动.当磁场只施加在二维电子气中时,量子点中的电导是自旋无极化的;但是当量子点的能级发生塞曼分裂时,电导中自旋朝上和朝下电导的尖峰在能量空间向相反方向移动,但保持大小不变.计算结果还发现两个量子点能级的差会在电导的Dicke尖峰附近产生额外的谷,并降低尖峰的高度.所研究的结构有望用于自旋过滤或分离装置.
Spin-polarized transport through a double quantum dot coupled to two-dimensional electron gases(2DEG)under magnetic field is investigated.The results show that when the two dots are close to each other enough,asymmetric sharp peak in the conductance induced by Dicke effect emerges.With increasing distance between the dots,the Dicke peak shifts to lower energy regimes with reduced peak height.When the magnetic field is applied only on the 2DEG,the conductance of the dots is spin-independent,whereas it becomes spin-polarized in the presence of finite Zeeman splitting of the dots’levels.The peaks’height of the spin-up and spin-down conductance remain the same.The numerical results also show that the difference between the dots’levels will induce additional dip near the Dicke peak and will reduces the magnitude of the peak in the conductance.The present structure may be used for filtering or splitting of electron spins.
作者
王宇鹏
WANG Yupeng(Editorial Department of Journal,Bohai University,Jinzhou 121013,China)
出处
《渤海大学学报（自然科学版）》
CAS
2019年第1期69-74,共6页
Journal of Bohai University:Natural Science Edition
基金
国家自然科学基金项目(No:10704011)
关键词
量子点
二维电子气
自旋极化输运
quantum dots
two-dimensional electron gases
spin-polarized transport
