  We present a non-Markovian quantum jump approach for simulating coherent
energy transfer dynamics in molecular systems in the presence of laser fields.
By combining a coherent modified Redfield theory (CMRT) and a non-Markovian
quantum jump (NMQJ) method, this new approach inherits the broad-range validity
from the CMRT and highly efficient propagation from the NMQJ. To implement NMQJ
propagation of CMRT, we show that the CMRT master equation can be casted into a
generalized Lindblad form. Moreover, we extend the NMQJ approach to treat
time-dependent Hamiltonian, enabling the description of excitonic systems under
coherent laser fields. As a benchmark of the validity of this new method, we
show that the CMRT-NMQJ method accurately describes the energy transfer
dynamics in a prototypical photosynthetic complex. Finally, we apply this new
approach to simulate the quantum dynamics of a dimer system coherently excited
to coupled single-excitation states under the influence of laser fields, which
allows us to investigate the interplay between the photoexcitation process and
ultrafast energy transfer dynamics in the system. We demonstrate that
laser-field parameters significantly affect coherence dynamics of
photoexcitations in excitonic systems, which indicates that the photoexcitation
process must be explicitly considered in order to properly describe
photon-induced dynamics in photosynthetic systems. This work should provide a
valuable tool for efficient simulations of coherent control of energy flow in
photosynthetic systems and artificial optoelectronic materials.
