  The presence of static off-diagonal disorder promotes coherent exciton
transport while diffusive motion can be recovered in the presence of
fluctuations in the diagonal and off-diagonal elements of the Hamiltonian. Here
we study the crossover induced by correlated dynamical disorder.We uncover a
novel role of the excited bath states (ExBS) in dictating quantum coherence and
quantum transport in dissipative quantum systems interacting with correlated
bath.We solve both analytically and numerically the temperature dependent
Quantum Stochastic Liouville equation (TD-QSLE) to study temperature dependence
of quantum coherence in both linear chains and cyclic trimer (first three
subunits of Fenna-Matthews-Olson(FMO) and also heptamer) complexes, using
Haken-Strobl-Reineker Hamiltonian. In the non-Markovian limit where the
lowering of temperature induces long-lasting quantum coherences, ExBSnot only
determines the lifetime of coherences but also dictates the long time
population distribution. We find a parallelism between classical and quantum
systems through transitions among excited bath states that provides a deeper
insight about role of temperature in equilibrium distribution.The effects of
dynamic disorder and excited bath stat eon quantum entanglement (through the
calculation of concurrence) in single exciton manifold are demonstrated.
