Advertisement

Self Consistent Model for Tunneling Across a One Dimensional Barrier in a Many Electron System

  • J. W. Halley
  • David Dahl

Abstract

We consider a model with two metals (modeled for the present as jellium) separated by a barrier described by a potential V(x). We show that the current density j can be fixed by adding a term H’ to the energy which is of the form:
$$H' = - m\int_{ - \infty }^\infty {v(x)j(x)d^3 x}$$
where v(x) is a Lagrange multiplier function which depends on the position x. We show that v(x) may be interpreted as the hydrodynamic velocity of the electrons in the junction so that v(x) depends on the electron density n(x) as j = < n(x) > v(x). The expectation value of j(x) is independent of x by current conservation. The computational part of the tunneling problem is thus reduced to the self-consistent solution of the Schroedinger equation with one additional term:
$$\left( {H_o - mv(x)^2 /2} \right)\varphi _p (x) = E_p \varphi _p (x)$$
This equation is solved self-consistently with boundary conditions appropriate to waves incident from the left and right (which form an orthonormal complete set when appropriately normalized). The result shows that, within this model, a finite current can pass through the barrier with no electrostatic potential drop. We will argue that this result does not depend on the local density approximation (which is the only computational approximation in the model) but is to be expected because there is no dissipative mechanism in the model.

Keywords

Local Density Approximation Current Conservation Slater Determinant Schroedinger Equation Kohn Sham 
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.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1a.
    J. A. Appelbaum and W. F. Brinkman, Phys. Rev. 186, 464 (1969)CrossRefGoogle Scholar
  2. 1b.
    J. A. Appelbaum and W. F. Brinkman, Phys. lev. B 6, 907 (1970)CrossRefGoogle Scholar
  3. 1c.
    C. B. Duke, G. C. Kleinman and T. E. Stakelon, Phys. Rev. B 6, 2389 (1972)CrossRefGoogle Scholar
  4. 1d.
    C. Caroli, R. Combescot, P. Nozieres and D. Saint James, J. Phys. C 4, 916 (1971)CrossRefGoogle Scholar
  5. 1e.
    C. Caroli, R. Combescot, P. Nozieres and D. Saint James, J. Phys. C 4, 2589 (1971)Google Scholar
  6. 1g.
    T. E. Feuchtwang, Phys. Rev. B 10, 4121 (1970)CrossRefGoogle Scholar
  7. 1g.
    T. E. Feuchtwang, Phys. Rev. B 11, 4135 (1974).CrossRefGoogle Scholar
  8. 2a.
    A. O. Caldeira and A. J. Leggett, Phys. Rev. Lett. 46, 211 (1981)CrossRefGoogle Scholar
  9. 2b.
    S. Chakravarty, Phys. Rev. Lett. 49, 681 (1981)CrossRefGoogle Scholar
  10. 2c.
    A. J. Bray and M. A. Moore, Phys. Rev. Lett. 49, 1546 (1982)CrossRefGoogle Scholar
  11. 2d.
    A. Schmid, Phys. Rev. Lett. 51,1506Google Scholar
  12. 2e.
    A. O. Caldeira and A. J. Leggett, Ann. Phys. 149, 374 (1983)CrossRefGoogle Scholar
  13. 2g.
    S. Chakravarty and A. J. Leggett, Phys. Rev. Lett. 52, 5 (1984)CrossRefGoogle Scholar
  14. 2h.
    L. -D. Chang and S. Chakravarty, Phys. Rev. Lett. B 29, 130 (1984).Google Scholar
  15. 3.
    J. Ferrante, J. R. Smith and J. H. Rose, General Motors Research Laboratories Publication GMR-4714 (1984).Google Scholar
  16. 4.
    N. D. Lang and W. Kohn, Phys. Rev. B 1, 4555 (1970).CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1987

Authors and Affiliations

  • J. W. Halley
    • 1
  • David Dahl
    • 2
  1. 1.School of Physics and AstronomyUniversity of MinnesotaMinneapolisUSA
  2. 2.Physics DepartmentSt. Olaf CollegeNorthfiledUSA

Personalised recommendations