Dissipative system
From Free net encyclopedia
- Another meaning of "dissipative system" is one that dissipates heat, see heat dissipation.
A dissipative system (or dissipative structure) is an open system which is operating far from thermodynamic equilibrium within an environment that exchanges energy, matter or entropy. A dissipative system is characterized by the spontaneous appearance of a complex, sometimes chaotic, structure. The term dissipative structures was coined by Ilya Prigogine. It is also called steady-state open system and nonequilibrium open system.
A simple example is the Bénard cells. More complex examples include lasers, Belousov-Zhabotinsky reaction, or even life itself.
A formal, mathematical definition of a dissipative system as the action of a group on a measurable set is given in the article on wandering sets.
Quantum dissipative systems
As quantum mechanics relies heavily on Hamiltonian mechanics, it is not intrinsically able to describe dissipative systems. In principle one can couple weakly the system, say an oscillator, to a bath, i.e., an assembly of many oscillators in thermal equilibrium with a broad band spectrum, and trace (average) over the bath. This yields a master equation which is a special case of a more general setting called the Lindblad equation.