Abstract
Full control of multiple degrees of freedom of multiple particles represents a fundamental ability for quantum information processing. We experimentally demonstrate an 18-qubit Greenberger-Horne-Zeilinger entanglement by simultaneous exploiting three different degrees of freedom of six photons, including their paths, polarization, and orbital angular momentum. We develop high-stability interferometers for reversible quantum logic operations between the photons’ different degrees of freedom with precision and efficiencies close to unity, enabling simultaneous readout of outcome combinations of the 18-qubit state. A state fidelity of is measured, confirming the genuine entanglement of all 18 qubits.
- Received 19 April 2018
DOI:https://doi.org/10.1103/PhysRevLett.120.260502
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