The theory of entanglement-assisted quantum metrology


Zhou, S. (2020). The theory of entanglement-assisted quantum metrology. Perimeter Institute. https://pirsa.org/20020060


Zhou, Sisi. The theory of entanglement-assisted quantum metrology. Perimeter Institute, Feb. 12, 2020, https://pirsa.org/20020060


          @misc{ pirsa_PIRSA:20020060,
            doi = {10.48660/20020060},
            url = {https://pirsa.org/20020060},
            author = {Zhou, Sisi},
            keywords = {Other},
            language = {en},
            title = {The theory of entanglement-assisted quantum metrology},
            publisher = {Perimeter Institute},
            year = {2020},
            month = {feb},
            note = {PIRSA:20020060 see, \url{https://pirsa.org}}

Sisi Zhou Perimeter Institute for Theoretical Physics


The quantum Fisher information (QFI) measures the amount of information that a quantum state carries about an unknown parameter. Given a quantum channel, its entanglement-assisted QFI is the maximum QFI of the output state assuming an input state over the system and an arbitrarily large ancilla. Consider N identical copies of a quantum channel, the channel QFI grows either linearly or quadratically with N asymptotically. Here we obtain a simple criterion that determines whether the scaling is linear or quadratic. In both cases, we found a quantum error correction protocol achieving the channel QFI asymptotically and an SDP to solve the optimal code.