title: Time-dependent quantum transport behavior through T-shaped double quantum dots.
abstract: The time-dependent current flowing through a T-shaped double quantum dot is theoretically studied via nonequilibrium Green's function methods. Quantum coherent ringing or beats can appear in the transient current after a bias voltage is turned on or off, and their periods can be tuned by the pulse bias or the interdot coupling strength. In the weak interdot coupling case no quantum beat is observed and only quantum ringing appears in the current, the frequency of which depends on the pulse bias. In the strong interdot coupling case, quantum beats appear in the current and their frequency depends on the interdot coupling strength. Quantum beats are suppressed greatly by the large energy difference between the two quantum dots. In addition, quantum ringing and beats tend to disappear with increasing temperature.
authors.affiliation: Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100083, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Pan
authors.forename: Yinghui
authors.initials: Y
authors.lastname: Zhao