Symmetry-enhanced supertransfer of delocalized quantum states

TL;DR

This paper investigates how symmetries in delocalized multi-excitation quantum states can enhance transfer rates and decay processes, revealing supertransfer phenomena that could impact light-harvesting systems.

Contribution

It introduces the concept of supertransfer in symmetric multi-excitation states and analyzes its potential operational role in physical systems.

Findings

Superradiance leads to N-fold enhancement in decay and absorption rates.

Supertransfer enables hopping rates proportional to MN between symmetrized states.

Symmetries can influence quantum transport despite environmental decoherence.

Abstract

Coherent hopping of excitation rely 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 anomolously long diffusion lengths in nano-engineered assembly of light-harvesting complexes.