Perfect transfer of arbitrary continuous variable states across optical waveguide lattices

We demonstrate that perfect state transfer can be achieved in an optical waveguide lattice governed by a Hamiltonian with modulated nearest-neighbor couplings. In particular, we report the condition that the evolution Hamiltonian should satisfy to achieve perfect transfer of any continuous variable input state. The states that can be transmitted need not have any specific properties - they may be pure or mixed, Gaussian or non-Gaussian in character, and comprise an arbitrary number of modes. We illustrate that the proposed protocol is scalable to two- and three-dimensional waveguide geometries. With the help of local phase gates on all the modes, our results can also be applied to realize a SWAP gate between mirror-symmetric modes about the center of the waveguide setup.