环状耦合三量子点结构的电子输运性质

Electron Transport Properties of a Circularly Coupled Triple-Quantum-Dot Structure

采用修正速率方法研究了环状耦合三量子点系统的瞬态和稳态输运性质.推导了环状耦合三量子点系统的约化密度矩阵运动方程和流经系统的电流.数值计算结果表明:系统处在各状态的几率和流经系统的电流随时间呈现振荡行为.当时间足够长时,它们都趋于稳定值,表明系统达到了稳定状态.在外加磁场的作用下,稳定电流呈现以2π为周期的Aharonov-Bohm振荡.

Using the modified rate equations the transport properties of a circularly coupled triple- quantum-dot structure in both the temporary and stationary cases are systematically investigated. The rate equations for the reduced density matrix elements are derived together with the corresponding current for the triple-quantum-dot structure. The numerical results show that the electron-occupation probabilities in all states and the current flowing from the left lead to the right one showed the temporal oscillations. When the time is sufficiently long they become constant. In the presence of an external magnetic field, the stationary current exhibits a 2π-period Aharonov-Bohm oscillation.