Europhys. Lett.
Volume 70, Number 4, May 2005
Page(s) 457 - 463
Section Atomic and molecular physics
Published online 13 April 2005
Europhys. Lett., 70 (4), pp. 457-463 (2005)
DOI: 10.1209/epl/i2005-10018-2

Exact formula of the bridge-mediated donor-acceptor effective coupling

D. J. Bicout1, 2, F. Varchon1 and E. Kats1, 3

1  Institut Laue-Langevin - 6 rue Jules Horowitz, B.P. 156, 38042 Grenoble, France
2  Biomathematics and Epidemiology, ENVL-TIMC B.P. 83, 69280 Marcy l'Etoile, France
3  L. D. Landau Institute for Theoretical Physics, RAS - 117940 GSP-1, Moscow, Russia

received 20 January 2005; accepted in final form 24 March 2005
published online 13 April 2005

An exact expression of the bridge-mediated donor-acceptor effective coupling, Hda, is derived. For systems represented by a tight-binding Hamiltonian with nearest-neighbor interactions, we show that |Hda|2 is equal to the product over all squares of nearest-neighbor couplings divided by an appropriate product of level spacing of eigen energies of the Hamiltonian. These results are subsequently compared with those obtained using perturbation approaches.

34.70.+e - Charge transfer.
73.40.Gk - Tunneling.
82.30.Fi - Ion-molecule, ion-ion, and charge-transfer reactions.

© EDP Sciences 2005