Coherent states associated with tridiagonal Hamiltonians

Abstract

It has been shown that a positive semi-definite Hamiltonian H, that has a tridiagonal matrix representation in a given basis, can be represented in the form H = A{\dag}A, where A is a forward shift operator playing the role of an annihilation operator. Such representation endows H with rich supersymmetric properties yielding results analogous to those obtained by studying the Hamiltonian as a differential operator. Here, we study the coherent states which we define as being the eigenstates of the operator A. We explicitly find the expansion coefficients of these states in the given basis. We further identify a complete set of special coherent states which themselves can be used as basis. In terms of these special coherent states, we show that a general coherent state has the expansion form of a Lagrange interpolation scheme. As application of the developed formalism, we work out examples of systems having pure discrete, pure continuous, or mixed energy spectrum.