Eur. Phys. J. B 61, 427-432 (2008)
https://doi.org/10.1140/epjb/e2008-00092-2

Correlated electron current and temperature dependence of the conductance of a quantum point contact

¹ School of Physics, University of New South Wales, Sydney, 2052, Australia
² Budker Institute of Nuclear Physics, 630090 Novosibirsk, Russia

Corresponding author: ^a sushkov@phys.unsw.edu.au

Received: 5 April 2007
Revised: 7 August 2007
Published online: 5 March 2008

Abstract

We investigate finite temperature corrections to the Landauer formula due to electron–electron interaction within the quantum point contact. When the Fermi level is close to the barrier height, the conducting wavefunctions become peaked on the barrier, enhancing the electron–electron interaction. At the same time, away from the contact the interaction is strongly suppressed by screening. To describe electron transport we formulate and solve a kinetic equation for the density matrix of electrons. The correction to the conductance G is negative and strongly enhanced in the region 0.5 × 2e²/h ≤ G ≤ 1.0 × 2e²/h. Our results for conductance agree with the so-called “0.7 structure” observed in experiments.