Münster 1997 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 10: Niederdimensionale Systeme, Lokalisierung

TT 10.1: Vortrag

Dienstag, 18. März 1997, 14:30–14:45, F1

Electron transport in coupled one-dimensional systems of interacting fermions — •Enrico Arrigoni, Berthold Brendel, and Werner Hanke — Institut für Theoretische Physik
Universität Würzburg,
D-97074 Würzburg

We study the low-temperature transport of a doped two- and three-chain ladder system [1] in the presence of a barrier or of a low impurity concentration [2]. We focus on the effects of the electron-electron interaction by modeling the system with Hubbard-like chains coupled by a single-particle hopping.

Above a certain finite value of the electron-electron repulsion the low-temperature conductance is suppressed, despite the presence of dominant superconducting correlations, in both the two- and three-chain case. However, there is a region of repulsive interaction where perfect transmission across the barrier occurs. The difference with respect to the one-channel case (where the conductance is suppressed for any repulsive interaction) is due to a renormalization of the (even-mode) Luttinger-liquid parameter K_ρ,+ when band curvature is taken into account.

[1] M. Fabrizio, Phys. Rev. B 48, 15838 (1993).

[2] C. L. Kane and M. P. A. Fisher, Phys. Rev. B 46, 15233 (1992).