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Updated: Jul 13, 2026
06:42
Generation and Coherent Control of Pulsed Quantum Frequency Combs
Published on: June 8, 2018
Entanglement generation by Fock-state filtration.
K J Resch1, J L O'Brien, T J Weinhold
1Department of Physics & Centre for Quantum Computer Technology, University of Queensland, Brisbane, QLD 4072, Australia.
Physical Review Letters
|August 7, 2007
Summary
We developed a novel Fock-state filter that selectively blocks single photons while allowing photon pairs to pass. This quantum interference-based device enables coherent manipulation of photonic states, demonstrating entanglement generation.
Area of Science:
- Quantum optics
- Quantum information science
- Nonlinear optics
Background:
- Single photons and photon pairs are fundamental units in quantum information processing.
- Controlling the number of photons in optical systems is crucial for quantum technologies.
- Existing methods for photon manipulation often lack selectivity or scalability.
Purpose of the Study:
- To demonstrate a Fock-state filter capable of preferentially blocking single photons over photon pairs.
- To utilize higher-order quantum interference for achieving large conditional nonlinearities.
- To show the coherent operation of the filter by generating entanglement.
Main Methods:
- Employing linear optics, an ancilla photon, and measurement to create conditional nonlinearities.
- Utilizing higher-order quantum interference principles.
- Converting unentangled photon pairs to a path-entangled state using the filter.
- Performing quantum state tomography to quantify entanglement.
Main Results:
- Demonstrated a filter that preferentially blocks single photons over photon pairs.
- Achieved large conditional nonlinearities through higher-order quantum interference.
- Successfully converted unentangled photon pairs into a path-entangled state, proving coherent operation.
- Quantified the generated entanglement, measuring a tangle of T=(20+/-9)%.
Conclusions:
- The developed Fock-state filter provides a novel method for controlling photon statistics.
- The filter's coherent operation opens possibilities for entanglement generation and manipulation.
- This work advances the development of essential components for quantum information processing and quantum networking.
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