Volume 84, Number 2, October 2008
Article Number 27002
Number of page(s) 4
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 24 September 2008
EPL, 84 (2008) 27002
DOI: 10.1209/0295-5075/84/27002

High-temperature excess current and quantum suppression of electronic backscattering

G. Sonne1, L. Y. Gorelik2, R. I. Shekhter1 and M. Jonson1, 3

1   University of Gothenburg, Department of Physics - SE-412 96 Göteborg, Sweden, EU
2   Chalmers University of Technology, Department of Applied Physics - SE-412 96 Göteborg, Sweden, EU
3   Heriot-Watt University, School of Engineering and Physical Sciences - Edinburgh EH14 4AS, Scotland, UK, EU

received 17 April 2008; accepted in final form 31 August 2008; published October 2008
published online 24 September 2008

We consider the electronic current through a one-dimensional conductor in the ballistic transport regime and show that the quantum oscillations of a weakly pinned single-scattering target results in a temperature- and bias-voltage independent excess current at large bias voltages. This is a genuine quantum effect on transport that derives from an exponential reduction of electron backscattering in the elastic channel due to quantum delocalisation of the scatterer and from a suppression of low-energy electron backscattering in the inelastic channels caused by the Pauli exclusion principle. We show that both the mass of the target and the frequency of its quantum vibrations can be measured by studying the differential conductance and the excess current. We apply our analysis to the particular case of a weakly pinned ${\rm C}_{60}$ molecule encapsulated by a single-wall carbon nanotube and find that the discussed phenomena are experimentally observable.

72.10.-d - Theory of electronic transport; scattering mechanisms.
73.23.-b - Electronic transport in mesoscopic systems.
73.23.Ad - Ballistic transport.

© EPLA 2008