Speaker
Description
We show theoretically that a modulated longitudinal cavity-qubit coupling can be used to control the path taken by a multiphoton coherent-state wavepacket conditioned on the state of a qubit, resulting in a qubit-which-path (QWP) entangled state [1]. We further show that QWP states have a better potential sensitivity for quantum-enhanced phase measurements (characterized by the quantum Fisher information), than either NOON states or entangled coherent states having the same average number of photons. QWP states can generate long-range multipartite entanglement using strategies for interfacing discrete- and continuous-variable degrees-of-freedom. Entanglement can therefore be distributed in a quantum network via QWP states without the need for single-photon sources or detectors.
[1] Z. M. McIntyre and W. A. Coish, arXiv:2306.13573 (to appear in Phys. Rev. Lett.)
| Keyword-1 | entanglement |
|---|---|
| Keyword-2 | quantum metrology |
| Keyword-3 | quantum networks |
