Study of the Transmission and Reflection of Electron Waves through a Bridge System Consisting of Quan-tum Dots Using the Tight-Binding Approximation


  • Shakir AL-Saidi University of Thi-Qar



In this study, we treat tunneling similarly to the dispersion problem where the wave incident on the barrier is partly transmitted and partly reflected. The transport potential will be related to conduction using the tight-binding model, the steady-state formula, and the Landauer relationship. The tunnel was processed using a bridge model. We studied the effect of changing the size of the quantum dots that make the bridge on the probability of transmission and reflection, the effect of changing the number of quantum dots on them. The transmission and reflection spectrums were compared as functions of the system's energy spectrum. We also noticed the effect of the transmission and reflection spectrum on the conductivity of the system. The results that have been reached, and will contribute significantly to the manufacture of nano-devices in the not-too-distant ture.


F. Hund, "Zur deutung der molekelspektren. i," Zeitschrift für Physik, vol. 40, pp. 742-764, 1927.

J. C. Slonczewski, "Conductance and exchange coupling of two ferromagnets separated by a tunneling barrier," Physical Review B, vol. 39, p. 6995, 1989.

J. Mathon, "Tight-binding theory of tunneling giant magnetoresistance," Physical Review B, vol. 56, p. 11810, 1997.

R. Landauer, "Electrical resistance of disordered one-dimensional lattices," Philosophical Magazine, vol. 21, pp. 863-867, 1970.

W. Brinkman, R. Dynes, and J. Rowell, "Tunneling conductance of asymmetrical barriers," Journal of Applied Physics, vol. 41, pp. 1915-1921, 1970.

J. Bardeen, "Tunnelling from a many-particle point of view," Physical review letters, vol. 6, p. 57, 1961.

Y. Hancock, A. Uppstu, K. Saloriutta, A. Harju, and M. J. Puska, "Generalized tight-binding transport model for graphene nanoribbon-based systems," Physical Review B, vol. 81, p. 245402, 2010.

K. Nakada, M. Fujita, G. Dresselhaus, and M. S. Dresselhaus, "Edge state in graphene ribbons: Nanometer size effect and edge shape dependence," Physical Review B, vol. 54, p. 17954, 1996.

D. Porezag, T. Frauenheim, T. Köhler, G. Seifert, and R. Kaschner, "Construction of tight-binding-like potentials on the basis of density-functional theory: Application to carbon," Physical Review B, vol. 51, p. 12947, 1995.

T. Papadopoulos, I. Grace, and C. Lambert, "Control of electron transport through Fano resonances in molecular wires," Physical review b, vol. 74, p. 193306, 2006.

C. T. White, J. Li, D. Gunlycke, and J. W. Mintmire, "Hidden one-electron interactions in carbon nanotubes revealed in graphene nanostrips," Nano letters, vol. 7, pp. 825-830, 2007.

D. Gunlycke and C. T. White, "Tight-binding energy dispersions of armchair-edge graphene nanostrips," Physical Review B, vol. 77, p. 115116, 2008.

D. Gunlycke, D. Areshkin, and C. White, "Semiconducting graphene nanostrips with edge disorder," Applied Physics Letters, vol. 90, 2007.

M. Büttiker, Y. Imry, R. Landauer, and S. Pinhas, "Generalized many-channel conductance formula with application to small rings," Physical Review B, vol. 31, p. 6207, 1985.

G. Cuniberti, E. Maciá, A. Rodriguez, and R. Römer, "Tight-binding modeling of charge migration in DNA devices," Charge migration in DNA: Perspectives from physics, chemistry, and biology, pp. 1-20, 2007.

B. Giese and J. Amaudrut, "A.-K. K€ ohler, M. Spormann, S. Wessely," Nature, vol. 412, p. 318, 2001.

X.-Q. Li and Y. Yan, "Electrical transport through individual DNA molecules," Applied Physics Letters, vol. 79, pp. 2190-2192, 2001.

R. Gutiérrez, S. Mandal, and G. Cuniberti, "Dissipative effects in the electronic transport through DNA molecular wires," Physical Review B, vol. 71, p. 235116, 2005.

F. D. Mackey, Electron tunneling in the tight-binding approximation: The University of Alabama, 2016.

M. Alshahrani, Theory of Electron Transport in Molecular Structures: Lancaster University (United Kingdom), 2022.


Article Dates

Published: 2023-12-27

How to Cite

AL-Saidi, S. (2023). Study of the Transmission and Reflection of Electron Waves through a Bridge System Consisting of Quan-tum Dots Using the Tight-Binding Approximation. University of Thi-Qar Journal of Science, 10(2), 205–210.