Steady Bell State Generation via Magnon-Photon Coupling
Abstract
We show that parity-time (P T ) symmetry can be spontaneously broken in the recently reported energy level attraction of magnons and cavity photons. In the P T -broken phase, the magnon and photon form a high-fidelity Bell state with maximum entanglement. This entanglement is steady and robust against the perturbation of the environment, which is in contrast to the general wisdom that expects instability of the hybridized state when the symmetry is broken. This anomaly is further understood by the compete of non-Hermitian evolution and particle number conservation of the hybrid system. As a comparison, neither P T -symmetry breaking nor steady magnon-photon entanglement is observed inside the normal level repulsion case. Our results may open an exciting window to utilize magnon-photon entanglement as a resource for quantum information science.
- Publication:
-
Physical Review Letters
- Pub Date:
- February 2020
- DOI:
- arXiv:
- arXiv:1905.11117
- Bibcode:
- 2020PhRvL.124e3602Y
- Keywords:
-
- Condensed Matter - Mesoscale and Nanoscale Physics;
- Quantum Physics
- E-Print:
- 5 pages, 4 figures