S. Nonnenmacher et A. Voros, EIGENSTATE STRUCTURES AROUND A HYPERBOLIC POINT, Journal of physics. A, mathematical and general, 30(1), 1997, pp. 295-315
Using coherent-state representations of quantum mechanics (Bargmann, H
usimi, and stellar representations), we describe analytically the phas
e-space structure of the general eigenstates corresponding to a one-di
mensional bilinear hyperbolic Hamiltonian, H = pq or equivalently H =
1/2(P-2 - Q(2)). Their semiclassical behaviour is discussed for eigenv
alues either near or away from the separatrix energy {H = O}, especial
ly in the phase-space vicinity of the saddle-point (q, p) = (0, 0).