Coding with finite quantum systems
Apostol Vourdas · Physical Review A · 2002
Coding using quantum states in an angular-momentum $(2j+1)$-dimensional Hilbert space H is considered in this paper. A concatenated code is studied in two steps. In the first step the space ${H}^{N}$ is considered and the code is its subspace ${H}_{A}$ spanned by the direct products of N angular-momentum states with the same m. In the second step the space ${H}_{A}^{M}$ is considered and the code is its subspace ${H}_{B}$ spanned by the direct products of M angle states with the same m. It is shown that the code introduces redundancy with respect to any transformation.