Semiclassical transport in nearly symmetric quantum dots. II. Symmetry breaking due to asymmetric leads

Whitney, Robert S. and Schomerus, Henning and Kopp, Marten (2009) Semiclassical transport in nearly symmetric quantum dots. II. Symmetry breaking due to asymmetric leads. Physical Review E, 80 (5). 056210. ISSN 1539-3755

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Abstract

In this work—the second of a pair of articles—we consider transport through spatially symmetric quantum dots with leads whose widths or positions do not obey the spatial symmetry. We use the semiclassical theory of transport to find the symmetry-induced contributions to weak localization corrections and universal conductance fluctuations for dots with left-right, up-down, inversion, and fourfold symmetries. We show that all these contributions are suppressed by asymmetric leads; however, they remain finite whenever leads intersect with their images under the symmetry operation. For an up-down symmetric dot, this means that the contributions can be finite even if one of the leads is completely asymmetric. We find that the suppression of the contributions to universal conductance fluctuations is the square of the suppression of contributions to weak localization. Finally, we develop a random-matrix theory model which enables us to numerically confirm these results.

Item Type:
Journal Article
Journal or Publication Title:
Physical Review E
Uncontrolled Keywords:
/dk/atira/pure/researchoutput/libraryofcongress/qc
Subjects:
ID Code:
30800
Deposited By:
Deposited On:
07 Dec 2009 09:28
Refereed?:
Yes
Published?:
Published
Last Modified:
28 Nov 2020 00:58