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Numerical Study of the Higher Order Moments of Conductance Fluctuations in Mesoscopic Structures

  • M. Cahay
  • P. Marzolf
  • S. Bandyopadhyay
Chapter
Part of the The Springer International Series in Engineering and Computer Science book series (SECS, volume 113)

Abstract

It is well-known that the conductance of a disordered mesoscopic structure exhibits sample-specific fluctuations in a magnetic field due to quantum interference effects [1]. The magnetic field changes the phase-relationships between the various Feynman trajectories in the structure thereby causing the conductance to fluctuate. In this paper, we have performed a numerical study of conductance fluctuations. Instead of using a magnetic field, we have induced the fluctuations by randomly altering the impurity configuration within the structure. Changing the impurity configuration has the same effect as applying a magnetic field since both alter the phase-relationships between the various Feynman paths which causes the conductance to fluctuate1. In addition to studying the fluctuations, we have also examined the probability distribution of the 2-probe Landauer conductances and calculated various moments of the distribution. As expected, we find that the second moment of the distribution (the standard deviation or the rms value of the fluctuations) is close to the claimed universal value of e 2 /h [2], but its exact magnitude is somewhat affected by the presence of evanescent states.

Keywords

Magnetic Field High Order Moment Computational Electronics Conductance Distribution Evanescent Mode 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. [1]
    See, for example, B. L. Al’tshuler, Pis’ma Zh. Eksp. Teor. Fiz., 41, 530 (1985) [JETP Lett., 41, 648 (1985)].Google Scholar
  2. [2]
    See, for instance, P. A. Lee, Physica A, 140, 169 (1986).CrossRefGoogle Scholar
  3. [3]
    S. Bandyopadhyay and M. Cahay, these proceedingsGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1991

Authors and Affiliations

  • M. Cahay
    • 1
  • P. Marzolf
    • 2
  • S. Bandyopadhyay
    • 2
  1. 1.Nanoelectronics Laboratory and Department of Electrical and Computer EngineeringUniversity of CincinnatiCincinnatiUSA
  2. 2.Department of Electrical and Computer EngineeringUniversity of Notre DameNotre DameUSA

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