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Understanding the Nature of ICT-based Innovation Processes in Education - A Theoretical Framework for Informing Policy, Research and Action
Controlling conductance statistics of quantum wires by driving ac fields
We calculate the entire distribution of the conductance P(G) of a
one-dimensional disordered system --quantum wire-- subject to a time-dependent
field. Our calculations are based on Floquet theory and a scaling approach to
localization. Effects of the applied ac field on the conductance statistics can
be strong and in some cases dramatic, as in the high-frequency regime where the
conductance distribution shows a sharp cut-off. In this frequency regime, the
conductance is written as a product of a frequency-dependent term and a field
independent term, the latter containing the information on the disorder in the
wire. We thus use the solution of the Mel'nikov equation for time-independent
transport to calculate P(G) at any degree of disorder. At lower frequencies, it
is found that the conductance distribution and the correlations of the
transmission Floquet modes are described by a solution of the
Dorokhov-Mello-Pereyra-Kumar equation with an effective number of channels. In
the regime of strong localization, induced by the disorder or the ac field,
P(G) is a log-normal distribution. Our theoretical results are verified
numerically using a single-band Anderson Hamiltonian.Comment: 6 pages, 4 figures. V2: a new reference added. Minor correction
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