[1] Univ Messina, Dipartimento Sci Matemat & Informat Sci Fis & Sci, I-98166 Messina, Italy
[2] Univ Palermo, Dipartimento Ingn, Viale Sci, I-90128 Palermo, Italy
[3] RIKEN, Theoret Quantum Phys Lab, Wako, Saitama 3510198, Japan
[4] RIKEN Ctr Quantum Comp RQC, Wako, Saitama 3510198, Japan
[5] Univ Michigan, Phys Dept, Ann Arbor, MI 48109 USA