Vibrational instability due to coherent tunneling of electrons

Department of Applied Physics, Chalmers University of Technology and Göteborg University - SE-412 96 Göteborg, Sweden

Corresponding author: dima@fy.chalmers.se

Received: 7 January 2002
Accepted: 21 January 2002

Abstract

Effects of a coupling between the mechanical vibrations of a quantum dot placed between the two leads of a single-electron transistor and coherent tunneling of electrons through a single level in the dot has been studied. We have found that for bias voltages exceeding a certain critical value a dynamical instability occurs and mechanical vibrations of the dot develop into a stable limit cycle. The current-voltage characteristics for such a transistor were calculated and they seem to be in reasonably good agreement with recent experimental results for the single--molecule transistor by Park et al.  (Nature 407 (2000) 57).