  The dissipative dynamics of a two-qubit system is studied theoretically. We
make use of the Bloch-Redfield formalism which explicitly includes the
parameter-dependent relaxation rates. We consider the case of two flux qubits,
when the controlling parameters are the partial magnetic fluxes through the
qubits' loops. The strong dependence of the inter-level relaxation rates on the
controlling magnetic fluxes is demonstrated for the realistic system. This
allows us to propose several mechanisms for lasing in this four-level system.
