Coherent quantum transport in disordered systems: A unified polaron treatment of hopping and band-like transport
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Cao_Coherent quantum.pdf
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735.51 KB
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Author(s)
Lee, Chee Kong
Moix, Jeremy
Cao, Jianshu
Date Issued
April 2015
Journal
The Journal of Chemical Physics
Publisher
American Institute of Physics (AIP)
Citation
Lee, Chee Kong, Jeremy Moix, and Jianshu Cao. “Coherent Quantum Transport in Disordered Systems: A Unified Polaron Treatment of Hopping and Band-like Transport.” The Journal of Chemical Physics 142.16 (2015): 164103.© 2015 AIP Publishing LLC
Version
Final published version
Abstract
Quantum transport in disordered systems is studied using a polaron-based master equation. The polaron approach is capable of bridging the results from the coherent band-like transport regime governed by the Redfield equation to incoherent hopping transport in the classical regime. A non-monotonic dependence of the diffusion coefficient is observed both as a function of temperature and system-phonon coupling strength. In the band-like transport regime, the diffusion coefficient is shown to be linearly proportional to the system-phonon coupling strength and vanishes at zero coupling due to Anderson localization. In the opposite classical hopping regime, we correctly recover the dynamics described by the Fermi’s Golden Rule and establish that the scaling of the diffusion coefficient depends on the phonon bath relaxation time. In both the hopping and band-like transport regimes, it is demonstrated that at low temperature, the zero-point fluctuations of the bath lead to non-zero transport rates and hence a finite diffusion constant. Application to rubrene and other organic semiconductor materials shows a good agreement with experimental mobility data.
MIT Department
Massachusetts Institute of Technology. Department of Chemistry
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Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1063/1.4918736
