Information processing using three-qubit and qubit-qutrit encodings of   noncomposite quantum systems
  We study quantum information properties of a seven-level system realized by a particle in an one-dimensional square-well trap. Features of encodings of seven-level systems in a form of three-qubit or qubit-qutrit systems are discussed. We use the three-qubit encoding of the system in order to investigate subadditivity and strong subadditivity conditions for the thermal state of the particle. The qubit-qutrit encoding is employed to suggest a single qudit algorithm for calculation of parity of a bit string. Obtained results indicate on the potential resource of multilevel systems for realization of quantum information processing. 
A.A. Popov, E.O. Kiktenko, A.K. Fedorov, V.I. Man'ko
quant-ph