Berlin 2005 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 25: Correlated Electrons - Low-dimensional Systems: Models
TT 25.11: Vortrag
Dienstag, 8. März 2005, 12:30–12:45, TU H2053
Nonlinear ac conductivity of disordered interacting 1d electrons — •Bernd Rosenow and Thomas Nattermann — Institut für Theoretische Physik, Universität zu Köln, D-50932 Germany
We consider low energy charge transport in one-dimensional (1d) electron systems with short range interactions under the influence of a random potential. For not too attractive interactions, such systems are insulators and the ac conductivity σac ∼ ω2 ln(1/ω)2 is described by a modified Mott-Halperin law [1]. At zero frequency, charge transport is only possible by the tunneling of charge carriers and the nonlinear dc conductivity is characterized by I ∼ exp(− √E0/E) [2]. Combining RG and instanton methods, we calculate the nonlinear ac conductivity and discuss the crossover between the nonanalytic field dependence of the electric current at zero frequency and the linear ac conductivity at small electric fields and finite frequency [3].
[1] M. Fogler, Phys. Rev. Lett. 88, 186402 (2002).
[2] T. Nattermann, T. Giamarchi, and P. Le Doussal, Phys. Rev. Lett. 91, 056603 (2003).
[3] B. Rosenow and T. Nattermann, cond-mat/0408042.