  This work presents an exactly soluble scheme to address the problem of
optimal transfer of quantum states through a set of $s$ harmonic oscillators
composing a network with connected ends as a closed quantum circuit. For this
purpose we start from a general quadratic Hamiltonian form. The relationship
between the parameters of the Hamiltonian, the network size, and the time
interval required for such transfer are explicitly shown. Particular physical
realizations of this Hamiltonian, transfer of entangled states, including
transfer of states at the expense of a quantum entanglement, are also
considered.

Quantum Physics