Europhys. Lett.
Volume 69, Number 6, March 2005
Page(s) 1003 - 1009
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 16 February 2005
Europhys. Lett., 69 (6), pp. 1003-1009 (2005)
DOI: 10.1209/epl/i2004-10434-8

Conductance modulation of metallic carbon nanotubes by remote charged rings

S. Barraza-Lopez1, S. V. Rotkin2, Y. Li1 and K. Hess1

1  Department of Physics and Beckman Institute for Advanced Science and Technology University of Illinois at Urbana-Champaign - 405 North Mathews Avenue Urbana, IL 61801, USA
2  Physics Department, Lehigh University - 16 East Memorial Drive Bethlehem, PA 18015, USA

received 22 October 2004; accepted in final form 17 January 2005
published online 16 February 2005

We calculate the effects of a longitudinal electrostatic perturbation on a metallic single-wall carbon nanotube and demonstrate conductance modulation. Such external modulation would be completely screened in bulk 3D metals but is possible in SWNTs because their electrons are quasi-two-dimensional and can interact with a nearby system of charges. The resultant modulation of the conductance is determined by the strength of the self-consistent potential and its periodicity over shorter or longer distances. We employ the zero-temperature single-particle Green's function transport approach in the empirical tight-binding approximation to quantify the modulation of conductance and also consider the limit of a superlattice.

73.63.Fg - Nanotubes.
71.30.+h - Metal-insulator transitions and other electronic transitions.
73.23.Ad - Ballistic transport.

© EDP Sciences 2005