  Optimal state transfer of a single two-level system (TLS) coupled to an Ohmic
boson bath via off-diagonal TLS-bath coupling is studied by using optimal
control theory. In the weak system-bath coupling regime where the
time-dependent Bloch-Redfield formalism is applicable, we obtain the Bloch
equation to probe the evolution of the dissipative TLS in the presence of a
time-dependent external control field. By using the automatic differentiation
technique to compute the gradient for the cost functional, we calculate the
optimal transfer integral profile that can achieve an ideal transfer within a
dimer system in the FennaMatthews-Olson (FMO) model. The robustness of the
control profile against temperature variation is also analyzed.
