Abstract
We present a protocol for probing the state of a quantum system by its resonant coupling and entanglement with a meter system. By continuous measurement of a time evolving meter observable, we infer the evolution of the entangled systems and, ultimately, the state and dynamics of the system of interest. The photon number in a cavity field is thus resolved by simulated monitoring of the Rabi oscillations of a resonantly coupled two-level system, and we propose to regard this as a practical extension of quantum nondemolition measurements with applications in quantum metrology and quantum computing.
- Received 21 January 2022
- Accepted 26 August 2022
DOI:https://doi.org/10.1103/PhysRevLett.129.120402
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