Verifying multipartite entangled Greenberger-Horne-Zeilinger states via multiple quantum coherences
Abstract
The ability to generate and verify multipartite entanglement is an important benchmark for near-term quantum devices. We develop a scalable entanglement metric based on multiple quantum coherences and demonstrate experimentally on a 20-qubit superconducting device. We report a state fidelity of 0.5165 ±0.0036 for an 18-qubit GHZ state, indicating multipartite entanglement across all 18 qubits. Our entanglement metric is robust to noise and only requires measuring the population in the ground state; it can be readily applied to other quantum devices to verify multipartite entanglement.
- Publication:
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Physical Review A
- Pub Date:
- March 2020
- DOI:
- 10.1103/PhysRevA.101.032343
- arXiv:
- arXiv:1905.05720
- Bibcode:
- 2020PhRvA.101c2343W
- Keywords:
-
- Quantum Physics
- E-Print:
- 7+4 pages, comments welcome