Quantum transport in a chain of quantum dots with inhomogeneous size distribution and manifestation of 1D Anderson localization

Moon-Hyun Cha,Jeongwoon Hwang

doi:10.1038/s41598-020-73578-z

Abstract

The effect of inhomogeneous quantum dot (QD) size distribution on the electronic transport of one-dimensional (1D) QD chains (QDCs) is theoretically investigated. The non-equilibrium Green function method is employed to compute the electron transmission probabilities of QDCs. The ensemble averaged transmission probability shows a close agreement with the conductivity equation predicted by Anderson et al. for a disordered electronic system. The fidelity of quantum transport is defined as the transmission performance of an ensemble of QDCs of length N (N-QDCs) to assess the robustness of QDCs as a practical electronic device. We found that the fidelity of inhomogeneous N-QDCs with the standard deviation of energy level distribution σε is a Lorentzian function of variable Nσε2. With these analytical expressions, we can predict the conductance and fidelity of any QDC characterized by (N, σε). Our results can provide a guideline for combining the chain length and QD size distributions for high-mobility electron transport in 1D QDCs.

Highlights

The effect of inhomogeneous quantum dot (QD) size distribution on the electronic transport of onedimensional (1D) quantum dots (QDs) chains (QDCs) is theoretically investigated
While previous theoretical studies on QDs mainly examined the electronic properties of small QD systems[12,13,14,15,16,17], a recent study examined the effect of impurity QDs on the electron transport in two-dimensional (2D) QD solids, in which the impurity QD was introduced as a perturbation to a periodic p otential[18]
The tunneling Hamiltonian between the QD chains (QDCs) and electrodes is given as HT = tk1d1†akL + tkN dN† akR + H.c., (3)

Summary

Introduction

The effect of inhomogeneous quantum dot (QD) size distribution on the electronic transport of onedimensional (1D) QD chains (QDCs) is theoretically investigated. We investigate quantum transport in one-dimensional (1D) chains of non-uniform QDs by calculating the transmission probability.

Results

Conclusion