Cost Functions

A cost function quantifies the performance of the quantum network at a particular task. A cost function is evaluated for a given network ansatz and settings. In general, a quantum network cost function requires one or more executions of a PennyLane QNode.

For convenience, we provide example cost functions for quantum networks. Custom cost functions can be implemented using PennyLane.

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Contents:

• QNodes
• Linear Cost Functions
• Entropic Quantities
• The Magic Squares Game
• Partial Transpose Negativity
• Nonlocality Witnesses