Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:quant-ph/0301146 · Physical Review A

Entanglement and four-wave mixing effects in the dissipation-free nonlinear interaction of two photons at a single atom

Holger Friedrich Hofmann, Kunihiro Kojima, Shigeki Takeuchi, Keiji Sasaki

Published Oct 10, 2003• 42 citations
arXivHTMLPDF

Abstract

We investigate the nonlinear interaction between two photons in a single-input pulse at an atomic two-level nonlinearity. A one-dimensional model for the propagation of light to and from the atom is used to describe the precise spatiotemporal coherence of the two-photon state. It is shown that the interaction generates spatiotemporal entanglement in the output state similar to the entanglement observed in parametric down-conversion. A method of generating photon pairs from coherent pump light using this quantum-mechanical four-wave mixing process is proposed.

DOI
10.1103/physreva.68.043813

Related papers

Nonlinear interaction of two photons with a one-dimensional atom: Spatiotemporal quantum coherence in the emitted field

Kunihiro Kojima, Holger Friedrich Hofmann, Shigeki Takeuchi +1 more

The nonlinear photon-photon interaction mediated by a single two-level atom is studied theoretically based on a one-dimensional model of the field-atom interaction. This model allows us to determine the effects of an atomic nonlinearity on the spatiotemporal coherence of a two-photon state. Specifically, the complete two-photon output wave function can be obtained for any two-photon input wave function. It is shown that the quantum interference between the components of the output state associated with different interaction processes causes bunching and antibunching in the two-photon statistics. This theory may be useful for various applications in photon manipulation, e.g., quantum information processing using photonic qubits, quantum nondemolition measurements, and the generation of entangled photons.

arXiv:quant-ph/0301124•Physical Review A•Jul 2, 2003•86 citations

Quantum effects in the interaction of off-resonant coherent light with a single atom

Akihiro Yamaguchi, Holger Friedrich Hofmann

Well-controlled nonlinear interactions between light-field pulses and single atoms could be used to implement optical quantum information technologies based on qubits encoded in superpositions of coherent states of light. Here, we investigate the transformation of a coherent light field input at a single atom sufficiently far from resonance to limit the decoherence effects associated with random excitations of the atom. The conditions for suppressing multiphoton scattering to implement arbitrarily large shifts of the coherent light amplitude without decoherence are studied. It is shown that quantum-controlled coherent shifts can be achieved by sufficiently long coherent pulses, indicating the possibility of generating superpositions of coherent states with large amplitude differences. The dominant multiphoton scattering effect associated with four-wave mixing is also identified, and the spectral and temporal characteristics of the entangled photon pairs generated by this process are discussed.

arXiv:1303.5516•Physical Review A•Jul 8, 2013•0 citations

Tailored four-wave-mixing processes for optical quantum information science

Jesper B. Christensen

This thesis deals with applications of nonlinear four-wave mixing in the context of optical quantum information science. By enabling diverse functionalities such as single-photon generation, temporal shaping, and frequency conversion, four-wave mixing is a highly versatile tool for processing optical quantum information. The first part addresses the use of spontaneous four-wave mixing for generating entangled photon pairs with the particular property that the photons are uncorrelated in time and frequency. Two schemes are proposed to achieve this. The first proposal relies on a gradually varying interaction between two orthogonally polarized pump pulses in a birefringent waveguide. It is shown that, if the two pump pulses undergo a complete walk-through, the two generated photons emerge in orthogonal polarizations with uncorrelated- and tailorable time-frequency distributions. The second proposal deals with photon-pair generation in a microring resonator. In this setting, it is shown that a dual-pulse configuration can be used to excite- and subsequently de-excite the resonator on a sub-lifetime timescale. This turns out to strongly diminish time-frequency correlations. The second part considers the four-wave-mixing process Bragg scattering, which is known to enable noise-free frequency conversion. The Bragg-scattering process treated here, which occurs in a birefringent waveguide, is shown to allow for shape-preserving and strongly uni-directional conversion with a large acceptance bandwidth.

•Jan 1, 2018•1 citation

Induced Coherence via Spontaneous Four‐Wave Mixing in Atomic Ensembles

Jiho Park, Heonoh Kim, Han Seb Moon

Abstract Induced coherence was first demonstrated three decades ago in a proof‐of‐principle experiment using entangled photons from spontaneous parametric down‐conversion in nonlinear crystals. This phenomenon is considered an interesting instance of complementarity, which lies at the heart of quantum optics. Here, the first demonstration of induced coherence across two coupled interferometers based on spontaneous four‐wave mixing (SFWM) in two independent hot‐atomic‐vapor‐based entangled photon sources is reported. When both the pump and coupling lasers are split and interact with two warm 87 Rb atomic ensembles, single‐photon interference is observed between the two idler photons of the narrowband photon pairs, generated via SFWM from the two cascade‐type atomic systems. Furthermore, it is found that the phase memory effect arises from the phase of the bidirectional counter‐propagating pump and coupling lasers, respectively. This work takes an important step toward the transition to the era of quantum optics being driven by atomic ensembles from solid‐state systems.

Advanced Quantum Technologies•Jun 4, 2021•3 citations

Nonlinear Optics and Quantum Entanglement of Ultraslow Single Photons

Mikhail D. Lukin, Ataç İmamoğlu

Two light pulses propagating with slow group velocities in a coherently prepared atomic gas exhibit dissipation-free nonlinear coupling of an unprecedented strength. This enables a single-photon pulse to coherently control or manipulate the quantum state of the other. Processes of this kind result in generation of entangled states of radiation field and open up new prospectives for quantum information processing.

arXiv:quant-ph/9910094•Physical Review Letters•Feb 14, 2000•619 citations

Quantum nonlinear optics without photons

Roberto Stassi, Vincenzo Macrí, Anton Frisk Kockum +4 more

Spontaneous parametric down-conversion is a well-known process in quantum nonlinear optics in which a photon incident on a nonlinear crystal spontaneously splits into two photons. Here we propose an analogous physical process where one excited atom directly transfers its excitation to a pair of spatially separated atoms with probability approaching 1. The interaction is mediated by the exchange of virtual rather than real photons. This nonlinear atomic process is coherent and reversible, so the pair of excited atoms can transfer the excitation back to the first one: the atomic analog of sum-frequency generation of light. The parameters used to investigate this process correspond to experimentally demonstrated values in ultrastrong circuit quantum electrodynamics. This approach can be extended to realize other nonlinear interatomic processes, such as four-atom mixing, and is an attractive architecture for the realization of quantum devices on a chip. We show that four-qubit mixing can efficiently implement quantum repetition codes and, thus, can be used for error-correction codes.

arXiv:1702.00660•Physical Review A•Aug 9, 2017•80 citations
We investigate the nonlinear interaction between two photons in a single-input pulse at an atomic two-level nonlinearity. A one-dimensional model for the propagation of light to and from the atom is used to describe the precise spatiotemporal coherence of the two-photon state. It is shown that the interaction generates spatiotemporal entanglement in the output state similar to the entanglement observed in parametric down-conversion. A method of generating photon pairs from coherent pump light using this quantum-mechanical four-wave mixing process is proposed.
The nonlinear photon-photon interaction mediated by a single two-level atom is studied theoretically based on a one-dimensional model of the field-atom interaction. This model allows us to determine the effects of an atomic nonlinearity on the spatiotemporal coherence of a two-photon state. Specifically, the complete two-photon output wave function can be obtained for any two-photon input wave function. It is shown that the quantum interference between the components of the output state associated with different interaction processes causes bunching and antibunching in the two-photon statistics. This theory may be useful for various applications in photon manipulation, e.g., quantum information processing using photonic qubits, quantum nondemolition measurements, and the generation of entangled photons.
Well-controlled nonlinear interactions between light-field pulses and single atoms could be used to implement optical quantum information technologies based on qubits encoded in superpositions of coherent states of light. Here, we investigate the transformation of a coherent light field input at a single atom sufficiently far from resonance to limit the decoherence effects associated with random excitations of the atom. The conditions for suppressing multiphoton scattering to implement arbitrarily large shifts of the coherent light amplitude without decoherence are studied. It is shown that quantum-controlled coherent shifts can be achieved by sufficiently long coherent pulses, indicating the possibility of generating superpositions of coherent states with large amplitude differences. The dominant multiphoton scattering effect associated with four-wave mixing is also identified, and the spectral and temporal characteristics of the entangled photon pairs generated by this process are discussed.
This thesis deals with applications of nonlinear four-wave mixing in the context of optical quantum information science. By enabling diverse functionalities such as single-photon generation, temporal shaping, and frequency conversion, four-wave mixing is a highly versatile tool for processing optical quantum information. The first part addresses the use of spontaneous four-wave mixing for generating entangled photon pairs with the particular property that the photons are uncorrelated in time and frequency. Two schemes are proposed to achieve this. The first proposal relies on a gradually varying interaction between two orthogonally polarized pump pulses in a birefringent waveguide. It is shown that, if the two pump pulses undergo a complete walk-through, the two generated photons emerge in orthogonal polarizations with uncorrelated- and tailorable time-frequency distributions. The second proposal deals with photon-pair generation in a microring resonator. In this setting, it is shown that a dual-pulse configuration can be used to excite- and subsequently de-excite the resonator on a sub-lifetime timescale. This turns out to strongly diminish time-frequency correlations. The second part considers the four-wave-mixing process Bragg scattering, which is known to enable noise-free frequency conversion. The Bragg-scattering process treated here, which occurs in a birefringent waveguide, is shown to allow for shape-preserving and strongly uni-directional conversion with a large acceptance bandwidth.
Abstract Induced coherence was first demonstrated three decades ago in a proof‐of‐principle experiment using entangled photons from spontaneous parametric down‐conversion in nonlinear crystals. This phenomenon is considered an interesting instance of complementarity, which lies at the heart of quantum optics. Here, the first demonstration of induced coherence across two coupled interferometers based on spontaneous four‐wave mixing (SFWM) in two independent hot‐atomic‐vapor‐based entangled photon sources is reported. When both the pump and coupling lasers are split and interact with two warm 87 Rb atomic ensembles, single‐photon interference is observed between the two idler photons of the narrowband photon pairs, generated via SFWM from the two cascade‐type atomic systems. Furthermore, it is found that the phase memory effect arises from the phase of the bidirectional counter‐propagating pump and coupling lasers, respectively. This work takes an important step toward the transition to the era of quantum optics being driven by atomic ensembles from solid‐state systems.
Spontaneous parametric down-conversion is a well-known process in quantum nonlinear optics in which a photon incident on a nonlinear crystal spontaneously splits into two photons. Here we propose an analogous physical process where one excited atom directly transfers its excitation to a pair of spatially separated atoms with probability approaching 1. The interaction is mediated by the exchange of virtual rather than real photons. This nonlinear atomic process is coherent and reversible, so the pair of excited atoms can transfer the excitation back to the first one: the atomic analog of sum-frequency generation of light. The parameters used to investigate this process correspond to experimentally demonstrated values in ultrastrong circuit quantum electrodynamics. This approach can be extended to realize other nonlinear interatomic processes, such as four-atom mixing, and is an attractive architecture for the realization of quantum devices on a chip. We show that four-qubit mixing can efficiently implement quantum repetition codes and, thus, can be used for error-correction codes.