Summer School on Computational Materials Science
2002
University of Illinois, Urbana-Champaign

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Numerical Methods for the Solution of Quantum Ballistic Transport

Umberto Ravaioli - ravaioli@uiuc.edu

Department of Electrical and Computer Engineering, Computational Science and Engineering Program, Beckman Institute, and NCSA

University of Illinois at Urbana-Champaign


Outline of Lecture

  1. Time-dependent Schrödinger equation
    1. Implicit and explicit discretization
    2. 1-D discretization schemes
    3. 2-D Alternate Direction Implicit (ADI)
    4. Variable effective mass
    5. Absorbing boundary conditions
    6. Tight-binding Hamiltonian representation
  2. Time-independent transport with Schrödinger equation
    1. 1-D recursion algorithm
    2. Injection boundary conditions for equilibrium contacts: quantum and classical system
    3. Expressions for the current
    4. 1-D transport using transmission line theory
  3. 2-D Recursive Green's function in the tight-binding formalism
    1. Decomposition of the 2-D domain
    2. Numerical solution of Dyson's equation in terms of tight-binding Grenn's functions
    3. Transmission and  reflection coefficient
    4. Comparison with mode-matching approach

Background Articles

1.

"Numerical simulaton of mesoscopic systems with open boundaries using the multidimensional time-dependent Schrödinger equation", L.F. Register, U. Ravaioli, and K. Hess, Journal of Applied Physics, vol. 69, pp. 7153-7158, 1991. (720 KB PDF).  "Erratum" (55 KB PDF)

2.

"Theory for a quantum modulated transistor",F. Sols, M. Macucci, U. Ravaioli and K. Hess, Journal of Applied Physics, vol. 66, pp. 3892-3906, 1989. (3.0 MB PDF)

3.

"Quasi 3-D Green's-function simulation of coupled electron waveguides", M. Macucci, A.T. Galick and U. Ravaioli, Physical Review B, vol. 52, pp. 5210-5220 , 1995. (2.8 MB PDF)

   

Lecture 1

Numerical Methods for the Solution of Schrödinger Equation for Ballistic Transport
  Presentation - download (375 KB PDF)

Lab Exercises

  2-D Tight-Binding Green's Functions (TBGreen code) - download (65 KB PDF)

 


Last Updated August 13, 2002
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