  We investigate decoherence-free evolution (DFE) of quantum discord (QD) for
two initially-correlated qubits in two finite-temperature reservoirs using an
exactly solvable model. We study QD dynamics of the two qubits coupled to two
independent Ohmic reservoirs when the two qubits are initially prepared in
X-type quantum states. It is found that reservoir temperature significantly
affects the DFE dynamics. We show that it is possible to control the DFE and to
prolong the DFE time by choosing suitable parameters of the two-qubit system
and reservoirs.
