以Floquet理論分析奈米尺度系統的電子傳輸

Abstract

奈米尺度系統的電子傳輸常假設於寬帶極限之下，在此極限下，記憶效應會隨之忽略。在此論文中，我們將Floquet理論應用於奈米尺度系統之電子傳輸，探討在時變外加場之下記憶效應的多光子同調穿隧截止效應。以電極─雙量子點─電極系統為例，電極與量子點之交互作用假設為勞侖茲分佈函數時，探討記憶效應之影響以及多光子同調穿隧截止效應之物理機制。

Electron transport through nanoscale systems are often studied in the wide-band limit without taking the memory effect into consideration. In this thesis, we present a novel Floquet approach in electron transport through nanoscale systems beyond the wide-band limit to explore the multi-photon (MP) coherent destruction of tunneling (CDT) with memory effect in the presence of time-dependent driving field. As a case study, the time-averaged current is calculated in an electrode-double quantum dots-electrode system driven by a periodic field using single Lorentzian spectral density function and a detailed analysis is presented to illustrate the origin of MP-CDT as well as the significance of memory effect.