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Implementation of a quantum controlled-SWAP gate with photonic circuits
Takafumi Ono1,2, Ryo Okamoto1,2,3, Masato Tanida1,2
1Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0020, Japan.
Scientific Reports
|April 1, 2017
Summary
Researchers demonstrate a three-qubit controlled-SWAP (Fredkin) gate for photonic qubits, a crucial step for simplifying quantum circuits and enabling advanced quantum information science protocols like error correction.
Area of Science:
- Quantum information science
- Quantum computing
- Photonic quantum technologies
Background:
- Scalability challenges in current quantum circuits utilizing two-qubit gates.
- Potential of three-qubit gates for simplifying quantum circuit structures.
Purpose of the Study:
- To realize a functional controlled-SWAP (Fredkin) gate using photonic qubits.
- To assess the performance and applicability of the realized Fredkin gate in quantum information processing.
Main Methods:
- Implementation of a Fredkin gate for photonic qubits.
- Characterization of gate performance using fidelity measurements in the computational basis.
- Evaluation of output state fidelity for a 3-photon Greenberger-Horne-Zeilinger state.
Main Results:
- Achieved a fidelity of 0.85 in the computational basis.
- Obtained an output state fidelity of 0.81 for a 3-photon Greenberger-Horne-Zeilinger state.
- Estimated process fidelity of 0.77 for the implemented Fredkin gate.
Conclusions:
- The successful realization of a photonic Fredkin gate offers a pathway to more scalable and efficient quantum circuits.
- The demonstrated gate's fidelity supports its application in critical quantum protocols such as error correction and optimal cloning.
- This work advances the development of photonic quantum technologies for complex quantum information tasks.
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