Symmetry-enhanced supertransfer of delocalized quantum states

• Main Authors: Lloyd, Seth (Contributor), Mohseni, Masoud (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Mechanical Engineering (Contributor), Massachusetts Institute of Technology. Research Laboratory of Electronics (Contributor), W. M. Keck Foundation Center for Extreme Quantum Information Theory (Contributor)
• Format: Article
• Language: English
• Published: IOP Publishing, 2012-06-28T13:01:17Z.
• Subjects: Article
• Online Access: Get fulltext

 Coherent hopping of excitation relies on quantum coherence over physically extended states. In this work, we consider simple models to examine the effect of symmetries of delocalized multi-excitation states on the dynamical timescales, including hopping rates, radiative decay and environmental interactions. While the decoherence (pure dephasing) rate of an extended state over N sites is comparable to that of a non-extended state, superradiance leads to a factor of N enhancement in decay and absorption rates. In addition to superradiance, we illustrate how the multi-excitonic states exhibit 'supertransfer' in the far-field regime-hopping from a symmetrized state over N sites to a symmetrized state over M sites at a rate proportional to MN. We argue that such symmetries could play an operational role in physical systems based on the competition between symmetry-enhanced interactions and localized inhomogeneities and environmental interactions that destroy symmetry. As an example, we propose that supertransfer and coherent hopping play a role in recent observations of anomalously long diffusion lengths in nano-engineered assembly of light-harvesting complexes.