A. Orthey (CTP PAS), Dynamical monitoring in higher dimensions and the emergence of physical realism
Channel: Centrum Fizyki Teoretycznej PAN
Date: 2023-04-20

Dr. Alexandre Orthey (Center for Theoretical Physics, PAS).
Dynamical monitoring in higher dimensions and the emergence of physical realism.
To better understand the emergence of physical reality in quantum systems during the measurement procedure, we need a model that can interpolate between weak measurements and strong (projective) measurements in systems of any dimension. Although the quantum logic gates to perform that on qubits are known, e.g., A. Touil et al., PRL 128, 010401 (2022), the question remains open regarding general qudits. Using Heisenberg-Weyl operators, we explicitly find a unitary operator acting on qudits that can be adjusted to interpolate between weak and strong (projective) non-selective measurement regimes, resulting in the monitoring map, P. Dieguez et al., PRA 97, 022107 (2018).  Surprisingly, within our model, we found out that to get complete information of a higher dimensional system (dimension lt. 5), it is not sufficient to interact it with only one qudit of the same dimension. It is necessary to employ a bigger environment to obtain a strong regime. On the other side, weak non-selective measurements can be done with a smaller environment for any dimension. We hope that our research furnishes tools for developments in the foundations of quantum mechanics, but also in quantum metrology.
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