  We relate gate fidelities of experimentally realized quantum operations to
the broadcasting property of their ideal operations, and show that the more
parties a given quantum operation can broadcast to, the higher gate fidelities
of its experimental realization are in general. This is shown by establishing
the correspondence between two operational quantities, quantum state
shareability and quantum broadcasting. This suggests that, to assess an
experimental realization using gate fidelities, the worst case of realization
such as noisy operations should be taken into account and then compared to
obtained gate fidelities. In addition, based on the correspondence, we also
translate results in quantum state shareability to their counterparts in
quantum operations.
