Once the addition of energy into this state begins to decrease the amount of entropy, a negative temperature state is formed.
The power necessary to maintain this state is proportional to the number of modes within the system's bandwidth. Once the addition of energy into this state begins to decrease the amount of entropy, a negative temperature state is formed. This state occurs when a fast transition allows the on-rate of a metastable state to be faster than its off-rate, and is thus impossible in a (*) two-level system. Flashlamps and microwaves are used to achieve this condition via pumping, which occurs in a gain medium. Occurring when more particles are in an excited state than a ground state in a system, this is, For 10 points, what state where stimulated emission dominates spontaneous emission and is the basis of LASERs.
The power necessary to maintain this state is proportional to the number of modes within the system's bandwidth.
Population Inversion [prompt on Lasing or word forms of LASERs until the end]