Perfect controlled joint remote state preparation independent of entanglement degree of the quantum channel

• Controlled joint remote state preparation is considered.
• Quantum circuit is proposed to produce task-oriented partially entangled channel.
• The quantum channel parameter is given to the supervisor (not to the receiver).
• Unit success probability without additional resource/operations/measurement.
• Perfection is achieved regardless of the shared entanglement degree.

We construct a quantum circuit to produce a task-oriented partially entangled state and use it as the quantum channel for controlled joint remote state preparation. Unlike most previous works, where the parameters of the quantum channel are given to the receiver who can accomplish the task only probabilistically by consuming auxiliary resource, operation and measurement, here we give them to the supervisor. Thanks to the knowledge of the task-oriented quantum channel parameters, the supervisor can carry out proper complete projective measurement, which, combined with the feed-forward technique adapted by the preparers, not only much economizes (simplifies) the receiver's resource (operation) but also yields unit total success probability. Notably, such apparent perfection does not depend on the entanglement degree of the shared quantum channel. Our protocol is within the reach of current quantum technologies.