Spin coherent states as energy eigenstates of two coupled oscillators

We find that a set of energy eigenstates of two coupled oscillators (time-independent and/or explicitly time-dependent) are classified as the spin coherent states \tau>(j) according to the value of j in the Schwinger bosonic realization, where j is the spin value and tau is determined by the dynamic parameters in the Hamiltonian. We also show that the probability pi(-1) \<zeta\\tau> (j) \(2) is just the marginal distribution of the Wigner function of \tau>(j) in the zeta-space, where <zeta\\ is the bipartite entangled state. (C) 2004 Elsevier B.V. All rights reserved.