Wigner Function Negativity and Contextuality in Quantum Computation on Rebits
Nicolas Delfosse, Philippe Allard Guerin, Jacob Bian, Robert Raussendorf · Physical Review X · 2015
Quantum computation commonly relies on qubits, but rebits---states with real density matrices---can be used as well. Researchers show how the contextuality of two-level states is necessary for quantum computation.