We consider the phase space for $n$ identical qudits (each one of dimension $d$, with $d$ a primer number) as a grid of $d^n\times d^n$ points and use the finite Galois field $\text{GF}\left(d^n\right)$ to label the corresponding axes. The associated displacement operators permit to define $s$-parametrized quasidistributions on this grid, with properties analogous to their continuous counterparts. These displacements allow also for the construction of finite coherent states, once a fiducial state is fixed. We take this reference as one eigenstate of the discrete Fourier transform and study the factorization properties of the resulting coherent states. We extend these ideas to include discrete squeezed states, and show their intriguing relation with entangled states of different qudits.

• Received 3 August 2009

DOI:https://doi.org/10.1103/PhysRevA.80.043836