Dissipationless states in dissipative systems

A general system comprising interacting dynamic and dissipative subsystems has been considered. It is shown that there exists a certain range of the system Hamiltonian parameters in which the system reveals dissipationless, reversible behavior. The criteria of the dissipationless region have been applied to the spin-boson system. At the energy difference ℏΔ0 (of two spin states) smaller than a certain critical energy ℏΔ0cr, the spin-boson system becomes dissipationless. Particularly, frictionless tunneling beats appear – supertunneling.