B. Crespi et al., QUANTUM POINCARE SECTIONS FOR 2-DIMENSIONAL BILLIARDS, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 47(2), 1993, pp. 986-991
We show a method to extract the quantum Poincare section corresponding
to an eigenstate of a two-dimensional billiard. This quantum Poincare
section is given in terms of the Birkhoff variables of the problem.