Cloning of observables
arXiv:quant-ph/0509170 · doi:10.1088/0305-4470/39/14/L02
Abstract
We introduce the concept of cloning for classes of observables and classify cloning machines for qubit systems according to the number of parameters needed to describe the class under investigation. A no-cloning theorem for observables is derived and the connections between cloning of observables and joint measurements of noncommuting observables are elucidated. Relationships with cloning of states and non-demolition measurements are also analyzed.
revised and enlarged version, 2 figures