ANALYTIC CALCULATION OF ARBITRARY MATRIX-ELEMENTS FOR BOSON EXPONENTIAL QUADRATIC OPERATORS

By means of the transformation relation between the ordinary form of b osom exponential quadratic operators (BEQO) and its anti-normal produc t form, we present an effective method to conveniently calculate arbit rary matrix elements of BEQO. By this method, many important matrix el ements can be calculated analytically As a direct application, we obta in the exact solutions of the density matrix and partition function fo r general boson quadratic Hamiltonian without any information about th e energy level.