Conductance stability in chaotic and integrable quantum dots with random impurities

Guanglei Wang, Lei Ying, Ying-Cheng Lai

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

For a quantum dot system of fixed geometry, in the presence of random impurities the average conductance over an appropriate range of the Fermi energy decreases as the impurity strength is increased. Can the nature of the corresponding classical dynamics in the dot region affect the rate of decrease? Utilizing graphene quantum dots with two semi-infinite, single-mode leads as a prototypical model, we address the device stability issue by investigating the combined effects of classical dynamics and impurities on the average conductance over the energy range of the first transverse mode. We find that, for chaotic dot systems, the rate of decrease in the average conductance with the impurity strength is in general characteristically smaller than that for integrable dots. We develop a semiclassical analysis for the phenomenon and also obtain an understanding based on the random matrix theory. Our results demonstrate that classical chaos can generally lead to a stronger stability in the device performance, strongly advocating exploiting chaos in the development of nanoscale quantum transport devices.
Original languageEnglish
Article number022901
Number of pages10
JournalPhysical Review. E, Statistical, Nonlinear and Soft Matter Physics
Volume92
Issue number2
DOIs
Publication statusPublished - 3 Aug 2015

Fingerprint

Quantum Dots
Conductance
Impurities
quantum dots
impurities
Decrease
chaos
Chaos
Semi-classical Analysis
Quantum Transport
Strong Stability
Random Matrix Theory
Graphene
matrix theory
Single Mode
Energy
Range of data
graphene
Transverse
energy

Keywords

  • Conductance stability
  • quantum dots
  • random impurities

Cite this

Conductance stability in chaotic and integrable quantum dots with random impurities. / Wang, Guanglei; Ying, Lei; Lai, Ying-Cheng.

In: Physical Review. E, Statistical, Nonlinear and Soft Matter Physics, Vol. 92, No. 2, 022901, 03.08.2015.

Research output: Contribution to journalArticle

@article{e4e9cba43fc14672844d40c084b7fa12,
title = "Conductance stability in chaotic and integrable quantum dots with random impurities",
abstract = "For a quantum dot system of fixed geometry, in the presence of random impurities the average conductance over an appropriate range of the Fermi energy decreases as the impurity strength is increased. Can the nature of the corresponding classical dynamics in the dot region affect the rate of decrease? Utilizing graphene quantum dots with two semi-infinite, single-mode leads as a prototypical model, we address the device stability issue by investigating the combined effects of classical dynamics and impurities on the average conductance over the energy range of the first transverse mode. We find that, for chaotic dot systems, the rate of decrease in the average conductance with the impurity strength is in general characteristically smaller than that for integrable dots. We develop a semiclassical analysis for the phenomenon and also obtain an understanding based on the random matrix theory. Our results demonstrate that classical chaos can generally lead to a stronger stability in the device performance, strongly advocating exploiting chaos in the development of nanoscale quantum transport devices.",
keywords = "Conductance stability, quantum dots, random impurities",
author = "Guanglei Wang and Lei Ying and Ying-Cheng Lai",
year = "2015",
month = "8",
day = "3",
doi = "10.1103/PhysRevE.92.022901",
language = "English",
volume = "92",
journal = "Physical Review. E, Statistical, Nonlinear and Soft Matter Physics",
issn = "1539-3755",
publisher = "AMER PHYSICAL SOC",
number = "2",

}

TY - JOUR

T1 - Conductance stability in chaotic and integrable quantum dots with random impurities

AU - Wang, Guanglei

AU - Ying, Lei

AU - Lai, Ying-Cheng

PY - 2015/8/3

Y1 - 2015/8/3

N2 - For a quantum dot system of fixed geometry, in the presence of random impurities the average conductance over an appropriate range of the Fermi energy decreases as the impurity strength is increased. Can the nature of the corresponding classical dynamics in the dot region affect the rate of decrease? Utilizing graphene quantum dots with two semi-infinite, single-mode leads as a prototypical model, we address the device stability issue by investigating the combined effects of classical dynamics and impurities on the average conductance over the energy range of the first transverse mode. We find that, for chaotic dot systems, the rate of decrease in the average conductance with the impurity strength is in general characteristically smaller than that for integrable dots. We develop a semiclassical analysis for the phenomenon and also obtain an understanding based on the random matrix theory. Our results demonstrate that classical chaos can generally lead to a stronger stability in the device performance, strongly advocating exploiting chaos in the development of nanoscale quantum transport devices.

AB - For a quantum dot system of fixed geometry, in the presence of random impurities the average conductance over an appropriate range of the Fermi energy decreases as the impurity strength is increased. Can the nature of the corresponding classical dynamics in the dot region affect the rate of decrease? Utilizing graphene quantum dots with two semi-infinite, single-mode leads as a prototypical model, we address the device stability issue by investigating the combined effects of classical dynamics and impurities on the average conductance over the energy range of the first transverse mode. We find that, for chaotic dot systems, the rate of decrease in the average conductance with the impurity strength is in general characteristically smaller than that for integrable dots. We develop a semiclassical analysis for the phenomenon and also obtain an understanding based on the random matrix theory. Our results demonstrate that classical chaos can generally lead to a stronger stability in the device performance, strongly advocating exploiting chaos in the development of nanoscale quantum transport devices.

KW - Conductance stability

KW - quantum dots

KW - random impurities

U2 - 10.1103/PhysRevE.92.022901

DO - 10.1103/PhysRevE.92.022901

M3 - Article

VL - 92

JO - Physical Review. E, Statistical, Nonlinear and Soft Matter Physics

JF - Physical Review. E, Statistical, Nonlinear and Soft Matter Physics

SN - 1539-3755

IS - 2

M1 - 022901

ER -