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Generation and Coherent Control of Pulsed Quantum Frequency Combs
Published on: June 8, 2018
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Coherent frequency down-conversions and entanglement generation in a Sagnac interferometer
Optics Express
|August 10, 2017
Summary
This study demonstrates generating two-qubit entangled states using a Sagnac interferometer with two emitters. Quantum interference enables frequency down-conversion, creating stable entanglement robust to dissipation.
Area of Science:
- Quantum optics
- Quantum information science
- Solid-state physics
Background:
- Sagnac interferometers are key for quantum experiments.
- Quantum emitters coupled to waveguides enable light-matter interactions.
- Entanglement generation is crucial for quantum technologies.
Purpose of the Study:
- To propose a scheme for generating two-qubit entangled states using a Sagnac interferometer and two Λ-type three-level emitters.
- To investigate the role of quantum interference in frequency down-conversion for entanglement.
- To assess the robustness of the proposed scheme against dissipation and photon wavepacket bandwidth.
Main Methods:
- Utilizing a Sagnac interferometer with two symmetrically coupled Λ-type three-level emitters.
- Inputting a single photon into the interferometer to induce coherent scattering.
- Analyzing quantum interference effects leading to frequency down-conversion and entanglement.
Main Results:
- Demonstrated that coherent frequency down-conversion at emitters leads to the generation of maximally entangled two-qubit states (symmetric or antisymmetric).
- Showcased that the entanglement arises from indistinguishable down-conversion processes, not photon localization.
- Confirmed the stability of entangled states if lower-lying emitter states are non-decaying.
Conclusions:
- The proposed scheme reliably generates stable two-qubit entangled states.
- The method is robust against emitter dissipation and finite photon bandwidth.
- This approach is feasible with current experimental technologies for quantum information processing.
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