TY - JOUR
T1 - Conductance stability in chaotic and integrable quantum dots with random impurities
AU - Wang, Guanglei
AU - Ying, Lei
AU - Lai, Ying-Cheng
N1 - Publisher Copyright:
© 2015 American Physical Society. ©2015 American Physical Society.
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.
UR - http://www.scopus.com/inward/record.url?scp=84939553320&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84939553320&partnerID=8YFLogxK
U2 - 10.1103/PhysRevE.92.022901
DO - 10.1103/PhysRevE.92.022901
M3 - Article
AN - SCOPUS:84939553320
SN - 1539-3755
VL - 92
JO - Physical Review E - Statistical, Nonlinear, and Soft Matter Physics
JF - Physical Review E - Statistical, Nonlinear, and Soft Matter Physics
IS - 2
M1 - 022901
ER -