Figure 4. Detecting quantum properties of the FMO complex.

Magnitude of the first witness [Eq. (4) for t − t₀ = τ] for the FMO complex assuming the final measurement is done on site m = 1 of the seven site FMO complex, for both (a) T = 77 K and (b) T = 300 K. A detection via our first witness is clearly visible for an initial evolution greater than t₀ = 0.3 ps at 77 K. In comparison, for same parameters we employ for the witness, the LG inequality only reveals a violation for upto 0.035 ps⁴⁴. (c) and (d) show the first witness with only limited access, i.e. with only state preparation and measurement on site 1. Quantum coherence is only detected when p₁(t₀)Ω₁₁(t, t₀) > 〈Q₁(t)〉. In all figures the bath parameters used were γ⁻¹ = 50 fs and λ = 35 cm⁻¹, and the Hamiltonian is the same as that used in Ref. 8. For the Hierarchy calculation, we used the “Ishizaki-Tanimura” truncation scheme and truncation as taken at K = 0 and N_c = 8 (see Methods, or Ref. 8, for the meaning of these parameters).