1202.3210 (A. Thilagam)

Multipartite entanglement in the Fenna-Matthews-Olson (FMO)
pigment-protein complex    [PDF]

A. Thilagam

We investigate the parameters involved in the long coherence times associated
with multipartite states in the Fenna-Matthews-Olson (FMO) pigment-protein
complex of the green sulfur bacteria. Using the time-convolutionless (TCL)
projection operator technique and a Lorentzian spectral density of the phonon
reservoir fitted with typical parameter estimates of the FMO complex species,
{P. aestuarii}, the evolution of the entanglement measure of the excitonic
qubit W states is evaluated in the picosecond time range, showing increased
revivals of the entanglement lasting up to 0.4 ps in the non-Markovian regime.
Similar trends are observed in the evolution dynamics of the Meyer-Wallach
measure of the N-excitonic qubit multipartite state, with results showing that
multipartite entanglement can last up to at least 0.5 ps,between the Bchls of
the FMO complex in a decoherent environment and at cryogenic temperatures.
Finally the teleportation and quantum information splitting fidelities [Chaves
et. al., Phys. Rev. A 82, 052308 (2010)] associated with the GHZ and W_{A}
resource states, are evaluated for excitonic qubit channels of the FMO complex
of species, {P. aestuarii}. Results show revivals in fidelities of resource
states increase with the degree of non-Markovian strength of the decoherent
environment. The W-like photosynthetic multipartite states provide greater
resilience to environmental related decoherence than the GHZ states. Results
indicate that quantum information processing tasks involving teleportation
followed by the decodification process involving W_{A} states of the FMO
complex, may play a critical role during coherent oscillations at physiological
temperatures.

View original: http://arxiv.org/abs/1202.3210