量子点环嵌入Aharonov-Bohm干涉器中电子的退耦合态及反共振现象

采用Anderson模型哈密顿量和非平衡态格林函数方法对量子点环以不同构型嵌入A-B干涉器中电子输运的退耦合态及反共振现象进行了理论研究. 结果表明,量子点环A-B干涉器的结构对称性以及穿过A-B干涉器的磁通量是诱发退耦合现象的两种物理机理. 耦合量子点结构的对称性越高,体系在相干电子输运过程中表现出来的退耦合及反共振现象越明显. 而且在具有高度对称性的耦合量子点结构中,通过磁场调节体系的结构参数可以分别使第奇数或第偶数分子本征态从电极上退耦合,从而使电子输运电导表现出奇偶对等振荡现象. 这为设计纳米电子开关器件提供了一个新的物理模型. 关键词： 量子点环 A-B干涉器 退耦合 反共振

Decoupled states and anti-resonance in the Aharonov-Bohm interferometer with embodied quantum-dot ring

Using the Anderson model Hamiltonian and the non-equilibrium Green's function method, the decoupled states and antiresonance presenting in the electronic transport through N-quantum-dot ring embodied in A-B interferometer are studied theoretically. We find that the symmetry of the coupled-dot system and the magnetic flux through the Aharonov-Bohm (A-B) interferometer are two physical mechanisms responsible for the decoupled states. Even-odd parity oscillations occur in linear conductance spectra of such a highly symmetric quantum dot ring, due to even or odd molecular state decoupling from the leads by tuning the structure parameters, i.e., the magnetic flux. The results provide a new model for the designing of the nano-device.