C. Uchiyama et F. Shibata, RIGOROUS SOLUTION TO A MICROSCOPIC LASER MODEL - FORMATION OF PHASE COHERENCE, Physics letters. A, 190(5-6), 1994, pp. 469-472
An extended version of a quantum statistical mechanical laser model is
solved rigorously. With the use of coherent states and orthogonal pol
ynomials, the original equation is solved to give a continued fraction
. The average of the induced atomic dipole moment is evaluated to give
the cooperative rotational motion.