Transition from diffusive to ballistic dynamics for a class of finite quantum models

Abstract

The transport of excitation probabilities amongst weakly coupled subunits is investigated for a class of finite quantum systems. It is demonstrated that the dynamical behavior of the transported quantity depends on the considered length scale, e. g., the introduced distinction between diffusive and ballistic transport appears to be a scale-dependent concept, especially since a transition from diffusive to ballistic behavior is found in the limit of small as well as in the limit of large length scales. All these results are derived by an application of the time-convolutionless projection operator technique and are verified by the numerical solution of the full time-dependent Schroedinger equation which is obtained by exact diagonalization for a range of model parameters.

4 pages, 5 figures, approved for publication in Physical Review Letters

References in corpus (3)

• Fourier's Law confirmed for a class of small quantum systems
• Fourier's Law in a Quantum Spin Chain and the Onset of Quantum Chaos
• Master-equations for the study of decoherence

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• Crossover from ballistic to diffusive thermal transport in quantum Langevin dynamics study of a harmonic chain connected to self-consistent reservoirs
• Reconstructing Fourier's law from disorder in quantum wires
• Photon-assisted tunneling in optical lattices: Ballistic transport of interacting boson pairs
• Equivalence of transport coefficients in bath-induced and dynamical scenarios
• Projection operator approach to transport in complex single-particle quantum systems