Transport in a disordered tight-binding chain with dephasing

Abstract

We study transport properties of a disordered tight-binding model (XX spin chain) in the presence of dephasing. Focusing on diffusive behavior in the thermodynamic limit at high energies, we analytically derive the dependence of conductivity on dephasing and disorder strengths. As a function of dephasing, conductivity exhibits a single maximum at the optimal dephasing strength. The scaling of the position of this maximum with disorder strength is different for small and large disorder. In addition, we study periodic disorder for which we find a resonance phenomenon, with conductivity having two maxima as a function of dephasing strength. If disorder is nonzero only at a random fraction of all sites, conductivity is approximately the same as in the case of a disorder on all sites but with a rescaled disorder strength.

13 pages; v2.: corrected wrong factor of 2 in conductivity

References in corpus (11)

• Dephasing assisted transport: Quantum networks and biomolecules
• Environment-Assisted Quantum Transport
• Highly efficient energy excitation transfer in light-harvesting complexes: The fundamental role of noise-assisted transport
• Tunneling through molecules and quantum dots: master-equation approaches
• Non-equilibrium Green s function based model for dephasing in quantum transport
• Solvable quantum nonequilibrium model exhibiting a phase transition and a matrix product representation
• Band-center anomaly of the conductance distribution in one-dimensional Anderson localization
• Disorder and dephasing effect on electron transport through conjugated molecular wires in molecular junctions
• Scaling and the center of band anomaly in a one-dimensional Anderson model with diagonal disorder
• Crucial role of decoherence for electronic transport in molecular wires: Polyaniline as a case study
• Statistical model for the effects of phase and momentum randomization on electron transport