Conductance in an Aharonov-Bohm Interferometer with Parallel-Coupled Double Dots
AN Xing-Tao1,2, ZHAO Jin-Rong1,2,3, LIU Jian-Jun1,2
1College of Physical Science and Information Engineering, Hebei Normal University, Shijiazhuang, Hebei 0500162Hebei Advanced Thin Films Laboratory, Shijiazhuang, Hebei 0500163First Middle School of Zhangjiakou, Zhangjiakou, Hebei 075000
Conductance in an Aharonov-Bohm Interferometer with Parallel-Coupled Double Dots
AN Xing-Tao1,2, ZHAO Jin-Rong1,2,3, LIU Jian-Jun1,2
1College of Physical Science and Information Engineering, Hebei Normal University, Shijiazhuang, Hebei 0500162Hebei Advanced Thin Films Laboratory, Shijiazhuang, Hebei 0500163First Middle School of Zhangjiakou, Zhangjiakou, Hebei 075000
摘要We present a theoretical study of the conductance in an Aharonov-Bohm interferometer containing two coupled quantum dots. The interdot tunneling divides the interferometer into two coupled subrings, where opposite magnetic fluxes are threaded separately while the net flux is kept zero. Using the Green function technique we derive the expression of the linear conductance. It is found that the Aharonov-Bohm effect still exists, and when the level of each dot is aligned, the exchange of the Fano and Breit-Wigner resonances in the conductance can be achieved by tuning the magnetic flux. When the two levels are mismatched the exchange may not happen. Further, for some specific asymmetric systems where the coupling strengths between the two dots and the leads are not equal, the flux can change the Fano resonance into an antiresonance, which is absent in symmetric systems.
Abstract：We present a theoretical study of the conductance in an Aharonov-Bohm interferometer containing two coupled quantum dots. The interdot tunneling divides the interferometer into two coupled subrings, where opposite magnetic fluxes are threaded separately while the net flux is kept zero. Using the Green function technique we derive the expression of the linear conductance. It is found that the Aharonov-Bohm effect still exists, and when the level of each dot is aligned, the exchange of the Fano and Breit-Wigner resonances in the conductance can be achieved by tuning the magnetic flux. When the two levels are mismatched the exchange may not happen. Further, for some specific asymmetric systems where the coupling strengths between the two dots and the leads are not equal, the flux can change the Fano resonance into an antiresonance, which is absent in symmetric systems.
AN Xing-Tao;ZHAO Jin-Rong;;LIU Jian-Jun;. Conductance in an Aharonov-Bohm Interferometer with Parallel-Coupled Double Dots[J]. 中国物理快报, 2009, 26(9): 97201-097201.
AN Xing-Tao, ZHAO Jin-Rong, , LIU Jian-Jun,. Conductance in an Aharonov-Bohm Interferometer with Parallel-Coupled Double Dots. Chin. Phys. Lett., 2009, 26(9): 97201-097201.
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2009, Vol. 26 
