ISSN - 14346028, EISSN - 14346036, European Physical Journal B, 2008, vol. 61, p. 427-432
Correlated electron current and temperature dependence of the conductance of a quantum point contact
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 × 2e 2/h ≤ G ≤ 1.0 × 2e 2/h. Our results for conductance agree with the so-called "0.7 structure" observed in experiments. © 2008 EDP Sciences/Società Italiana di Fisica/Springer-Verlag.