FMO-Based Biomolecular Which-Path Coupling in a Single-Photon Double-Slit Experiment

We present a theoretical and experimental framework for probing biomolecular which-path couplingusing an isolated, naturally asymmetric Fenna–Matthews–Olson (FMO) light-harvesting complexpositioned at one slit of a single-photon double-slit interferometer. The experimental roadmap isstructured into three sequential, independently publishable phases. Phase 1 is a 2DES characterisationof mutant FMO variants (∆bchQ, ∆bchR, ∆∆bchQR) to build the first experimental Γgeno table —distinct from and complementary to the well-characterised WT FMO literature. Phase 2 introducesJ-aggregate synthetic proxies as a proof-of-concept interferometry step, bridging the ~103× detectiongap before biological samples are used. Phase 3 then applies the validated framework to FMObiological samples. The photon–FMO interaction is modelled within the Lindblad open quantumsystems formalism; fringe-visibility reduction ∆V is expressed as a function of Förster/Redfieldcoupling strength J, pure dephasing rate γd, and spectral density J(ω). The proposal invokes nonon-standard quantum mechanics, consciousness-induced collapse, or observer-dependence; allpredicted effects follow from standard Lindblad dynamics.