|Instituto de Ciencia de Materiales de Madrid|
|Condensed Matter Theory|
|Sigmund Kohler||home | cv | research | publications|
Molecular wires acting as coherent quantum ratchetsJörg Lehmann, Sigmund Kohler, Peter Hänggi, and Abraham Nitzan
Phys. Rev. Lett. 88, 228305 (2002)
The effect of laser fields on electron transport through a molecular wire weakly coupled to two leads is investigated. The molecular wire acts as a coherent quantum ratchet if the molecule is composed of periodically arranged, asymmetric chemical groups. This setup presents a quantum rectifier with a finite dc response in the absence of a static bias. The nonlinear current is evaluated in closed form within the Floquet basis of the isolated, driven wire. The current response reveals multiple current reversals together with a nonlinear dependence on the amplitude and the frequency of the laser field. The current saturates for long wires at a nonzero value, while it may change sign upon decreasing its length.
[Condensed Matter Theory]
last modified: 25.10.2018 by Sigmund Kohler