Solution to the mean king's problem using quantum error-correcting codes
M. Yoshida, Gen Kimura, Takayuki Miyadera, Hideki Imai, Jun Cheng · Physical Review A · 2015
We discuss the so-called mean king's problem, a retrodiction problem among noncommutative observables, in the context of error detection. Describing the king's measurement effectively by a single error operation, we give a solution of the mean king's problem using quantum error-correcting codes. The existence of a quantum error-correcting code from a solution is also presented.