  The quench dynamics of a system involving two competing orders is
investigated using a Ginzburg-Landau theory with relaxational dynamics. We
consider the scenario where a pump rapidly heats the system to a high
temperature, after which the system cools down to its equilibrium temperature.
We study the evolution of the order parameter amplitude and fluctuations in the
resulting time dependent free energy landscape. Exponentially growing thermal
fluctuations dominate the dynamics. The system typically evolves into the phase
associated with the faster-relaxing order parameter, even if it is not the
global free energy minimum. This theory offers a natural explanation for the
widespread experimental observation that metastable states may be induced by
laser induced collapse of a dominant equilibrium order parameter.
