Detecting Large Quantum Fisher Information with Finite Measurement Precision
Detecting Large Quantum Fisher Information with Finite Measurement Precision
We propose an experimentally accessible scheme to determine the lower bounds on the quantum Fisher information (QFI), which ascertains multipartite entanglement or usefulness for quantum metrology. The scheme is based on comparing the measurement statistics of a state before and after a small unitary rotation. We argue that, in general, …