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Nanofabrication of Gate-defined GaAs/AlGaAs Lateral Quantum Dots
Published on: November 1, 2013
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Conductance stability in chaotic and integrable quantum dots with random impurities
Guanglei Wang1, Lei Ying1, Ying-Cheng Lai1,2
1School of Electrical, Computer, and Energy Engineering, Arizona State University, Tempe, Arizona 85287, USA.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|September 19, 2015
Summary
Classical chaos in graphene quantum dots enhances device stability against impurities. Chaotic systems show a slower decrease in conductance compared to integrable ones, suggesting chaos exploitation for robust nanoscale quantum transport devices.
Area of Science:
- Quantum physics
- Condensed matter physics
- Nanotechnology
Background:
- Impurities in quantum dot systems reduce average conductance as impurity strength increases.
- The influence of classical dynamics within the quantum dot on this conductance decrease is not well understood.
Purpose of the Study:
- To investigate how classical dynamics (integrable vs. chaotic) affects the stability of graphene quantum dot devices against random impurities.
- To determine if classical chaos can mitigate the detrimental effects of impurities on average conductance.
Main Methods:
- Utilized graphene quantum dots with two semi-infinite, single-mode leads as a model system.
- Studied the combined effects of classical dynamics and impurity strength on average conductance across the first transverse mode's energy range.
- Employed semiclassical analysis and random matrix theory for theoretical understanding.
Main Results:
- Chaotic quantum dot systems exhibit a characteristically smaller rate of decrease in average conductance with increasing impurity strength compared to integrable systems.
- Classical chaos generally leads to enhanced stability in device performance.
Conclusions:
- Classical dynamics significantly influences device stability in the presence of impurities.
- Exploiting classical chaos is a promising strategy for developing more robust nanoscale quantum transport devices.
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