PIRSA:24050015

Quantum metrological limits in noisy environments

Zhou, S. (2024). Quantum metrological limits in noisy environments. Perimeter Institute. https://pirsa.org/24050015

Zhou, Sisi. Quantum metrological limits in noisy environments. Perimeter Institute, May. 03, 2024, https://pirsa.org/24050015 

          @misc{ pirsa_PIRSA:24050015,
            doi = {10.48660/24050015},
            url = {https://pirsa.org/24050015},
            author = {Zhou, Sisi},
            keywords = {Quantum Information},
            language = {en},
            title = {Quantum metrological limits in noisy environments},
            publisher = {Perimeter Institute},
            year = {2024},
            month = {may},
            note = {PIRSA:24050015 see, \url{https://pirsa.org}}
          }

Sisi Zhou

Perimeter Institute for Theoretical Physics

Talk number
PIRSA:24050015
Collection
Talk Type
Subject
Abstract
The Heisenberg limit (HL) and the standard quantum limit (SQL) are two fundamental quantum metrological limits, which describe the scalings of estimation precision of an unknown parameter with respect to N, the number of one-parameter quantum channels applied. In the first part, we show the HL (1/N) is achievable using quantum error correction (QEC) strategies when the ``Hamiltonian-not-in-Kraus-span'' (HNKS) condition is satisfied; and when HNKS is violated, the SQL (1/N^1/2) is optimal and can be achieved with repeated measurements. In the second part, we identify modified metrological limits for estimating one-parameter qubit channels in settings of restricted controls where QEC cannot be performed. We prove unattainability of the HL and further show a ``rotation-generators-not-in-Kraus-span'' (RGNKS) condition that determines the achievability of the SQL.