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:2401.06997

How single-photon nonlinearity is quenched with multiple quantum emitters: Quantum Zeno effect in collective interactions with $Λ$-level atoms

Alexander N. Poddubny, Serge Rosenblum, Barak Dayan

Published Jan 13, 2024• 0 citations
arXivHTMLPDF

Abstract

Single-photon nonlinearity, namely the change in the response of the system as the result of the interaction with a single photon, is generally considered an inherent property of a single quantum emitter. Understanding the dependence of the nonlinearity on the number of emitters is important both fundamentally and practically, as strong light-matter coupling is more readily achieved through collective interactions than with a single emitter. Here, we theoretically consider a system that explores the transition from a single to multiple emitters with a $Λ$-level scheme. We show that the single-photon nonlinearity indeed vanishes with the number of emitters. Interestingly, the mechanism behind this behavior is the quantum Zeno effect, manifested in the slowdown of the photon-controlled dynamics.

DOI
10.48550/arxiv.2401.06997

Related papers

How Single-Photon Switching Is Quenched with Multiple Λ –Level Atoms

Alexander N. Poddubny, Serge Rosenblum, Barak Dayan

Single-photon nonlinearity, namely, the change in the response of the system as the result of the interaction with a single photon, is generally considered an inherent property of a single quantum emitter. Although the dependence on the number of emitters is well understood for the case of two-level systems, deterministic operations such as single-photon switching or photon-atom gates inherently require more complex level structures. Here, we theoretically consider single-photon switching in ensembles of emitters with a Λ-level scheme and show that the switching efficiency vanishes with the number of emitters. Interestingly, the mechanism behind this behavior is the quantum Zeno effect, manifested in a slowdown of the photon-controlled dynamics of the atomic ground states.

Physical Review Letters•Sep 11, 2024•5 citations

Single quantum emitter Dicke enhancement

Tommaso Tufarelli, Daniel Friedrich, Heiko Groß +3 more

Coupling $N$ identical emitters to the same field mode is a well-established method to enhance light-matter interaction. However, the resulting $\sqrt{N}$ boost of the coupling strength comes at the cost of a ``linearized'' (effectively semiclassical) dynamics. Here, we instead demonstrate a new approach for enhancing the coupling constant of a single quantum emitter, while retaining the nonlinear character of the light-matter interaction. We consider a single quantum emitter with $N$ nearly degenerate transitions that are collectively coupled to the same field mode. We show that in such conditions an effective Jaynes-Cummings model emerges with a boosted coupling constant of order $\sqrt{N}$. The validity and consequences of our general conclusions are analytically demonstrated for the instructive case $N=2$. We further observe that our system can closely match the spectral line shapes and photon autocorrelation functions typical of Jaynes-Cummings physics, proving that quantum optical nonlinearities are retained. Our findings match up very well with recent broadband plasmonic nanoresonator strong-coupling experiments and will, therefore, facilitate the control and detection of single-photon nonlinearities at ambient conditions.

arXiv:2010.12585•Physical Review Research•Jul 29, 2021•10 citations

Giant Photon Blockade with Multiple Atoms

Anonymous, Qinghong Liao, Qingyue Zhang +1 more

Nonlinearity at the single-photon level is important in both fundamental research and applications of quantum optics. Strong single-photon nonlinearity is usually hard to achieve with a single atom coupled to a cavity mode. Unfortunately, stronger nonlinearity cannot be achieved by coupling more atoms straightforwardly because of the gradual homogeneity of the system energy levels. Here we propose two proposals to realize deeper photon blockade with the increase of the atom number with the help of quantum Zeno dynamics. The single-photon blockade that manifests single-photon nonlinearity is achieved with high single-photon efficiency and purity. We developed a hybrid method by partitioning the system states into two subsets with one computed via a master equation and the other via a non-Hermitian Hamiltonian. This method significantly reduces computational resource requirements and enables simulations of systems with up to thousands of atoms. The results show that our proposals are robust against the inhomogeneity of atom frequency and coupling strength, which is favorable in experiments.

Physical Review Letters•Sep 4, 2026•0 citations

Realization of waveguide many-body quantum optics

Lena M. Hansen, Clara Henke, Christoph Hotter +13 more

Controlling light photon-by-photon is central to quantum optics. At a fundamental level, photon interactions are mediated by their coupling to atoms, and ultimate control requires deterministic light-matter interfacing of single photons to single atoms. Extending this paradigm to radiatively couple multiple individual atoms in a deterministic and scalable manner opens the arena of many-body quantum optics. Here, we realize such a setting by coherently coupling solid-state artificial atoms to a nanophotonic waveguide and demonstrate higher-order photon correlations that are controlled by the number of quantum emitters. We study the scaling of nonlinear photonic transport induced by emitter-photon scattering and demonstrate that adding a quantum emitter generates higher-order photon correlations. Specifically, we experimentally observe genuine three-photon correlations from a pair of collectively coupled emitters, while contributions from lower photon numbers are suppressed. In addition, we scale to three resonant quantum emitters coupled to the waveguide. These advancements demonstrate the onset of many-body quantum optics in waveguide quantum electrodynamics, enabling new photonic quantum simulators, the creation of many-body entangled states, and the exploration of novel quantum phase transitions.

quant-pharXiv:2605.18525•May 19, 2026•0 citations

Collective Enhancement of Photon Blockade via Two-Photon Interactions

Lijuan Dong, Aanal Jayesh Shah, Peter Kirton +2 more

Analogous to Coulomb blockade for electrons, photon blockade is a key quantum optical effect in which the presence of one photon prevents the transmission of subsequent ones through a nonlinear medium. Beyond its fundamental interest, photon and multi-photon blockade are actively studied as mechanisms for generating technologically-relevant quantum states of light. Although photon blockade typically requires achieving strong light-matter coupling, increasing the number of atoms fails to enhance antibunching. Here, we analyze the optical transmission properties of a quantum resonator that embeds a two-photon-coupled ensemble of emitters, combining an approximate analytical approach with full quantum numerical simulations. We show that when light and matter are coupled via a two-photon interaction, both single- and multi-photon blockade can benefit from a collective enhancement. We propose different driving schemes in which the second or third-order correlation functions are strongly suppressed with increasing atom number. Differently from established methods, this collective enhancement of non-classical properties occurs with unitary transmission and is ultimately constrained only by decoherence. This demonstrates that collective two-photon couplings are a powerful mechanism for realizing photon blockade even in platforms where individual strong coupling is not achievable.

quant-pharXiv:2511.11506•PRX Quantum•Nov 17, 2025•0 citations

Quantum theory of single-photon nonlinearities generated by ensembles of emitters

Kurt A. Jacobs, Stefan Krastanov, Mikkel Heuck +1 more

The achievement of sufficiently fast interactions between two optical fields at the few-photon level would provide a key enabler for a broad range of quantum technologies. One critical hurdle in this endeavor is the lack of a comprehensive quantum theory of the generation of nonlinearities by ensembles of emitters. Distinct approaches applicable to different regimes have yielded important insights: i) a semiclassical approach reveals that, for many-photon coherent fields, the contributions of independent emitters add independently allowing ensembles to produce strong optical nonlinearities via EIT; ii) a quantum analysis has shown that in the few-photon regime collective coupling effects prevent ensembles from inducing these strong nonlinearities. Rather surprisingly, experimental results with around twenty photons are in line with the semi-classical predictions. Theoretical analysis has been fragmented due to the difficulty of treating nonlinear many-body quantum systems. Here we are able to solve this problem by constructing a powerful theory of the generation of optical nonlinearities by single emitters and ensembles. The key to this construction is the application of perturbation theory to perturbations generated by subsystems. This theory reveals critical properties of ensembles that have long been obscure. The most remarkable of these is the discovery that quantum effects prevent ensembles generating single-photon nonlinearities only within the rotating-wave regime; outside this regime single-photon nonlinearities scale as the number of emitters. The theory we present here also provides an efficient way to calculate nonlinearities for arbitrary multi-level driving schemes, and we expect that it will prove a powerful foundation for further advances in this area.

arXiv:2307.01375•Jul 3, 2023•0 citations
How single-photon nonlinearity is quenched with multiple quantum emitters: Quantum Zeno effect in collective interactions with ΛΛΛ-level atoms
Single-photon nonlinearity, namely the change in the response of the system as the result of the interaction with a single photon, is generally considered an inherent property of a single quantum emitter. Understanding the dependence of the nonlinearity on the number of emitters is important both fundamentally and practically, as strong light-matter coupling is more readily achieved through collective interactions than with a single emitter. Here, we theoretically consider a system that explores the transition from a single to multiple emitters with a ΛΛΛ-level scheme. We show that the single-photon nonlinearity indeed vanishes with the number of emitters. Interestingly, the mechanism behind this behavior is the quantum Zeno effect, manifested in the slowdown of the photon-controlled dynamics.
Single-photon nonlinearity, namely, the change in the response of the system as the result of the interaction with a single photon, is generally considered an inherent property of a single quantum emitter. Although the dependence on the number of emitters is well understood for the case of two-level systems, deterministic operations such as single-photon switching or photon-atom gates inherently require more complex level structures. Here, we theoretically consider single-photon switching in ensembles of emitters with a Λ-level scheme and show that the switching efficiency vanishes with the number of emitters. Interestingly, the mechanism behind this behavior is the quantum Zeno effect, manifested in a slowdown of the photon-controlled dynamics of the atomic ground states.
Coupling NNN identical emitters to the same field mode is a well-established method to enhance light-matter interaction. However, the resulting N\sqrt{N}N​ boost of the coupling strength comes at the cost of a ``linearized'' (effectively semiclassical) dynamics. Here, we instead demonstrate a new approach for enhancing the coupling constant of a single quantum emitter, while retaining the nonlinear character of the light-matter interaction. We consider a single quantum emitter with NNN nearly degenerate transitions that are collectively coupled to the same field mode. We show that in such conditions an effective Jaynes-Cummings model emerges with a boosted coupling constant of order N\sqrt{N}N​. The validity and consequences of our general conclusions are analytically demonstrated for the instructive case N=2N=2N=2. We further observe that our system can closely match the spectral line shapes and photon autocorrelation functions typical of Jaynes-Cummings physics, proving that quantum optical nonlinearities are retained. Our findings match up very well with recent broadband plasmonic nanoresonator strong-coupling experiments and will, therefore, facilitate the control and detection of single-photon nonlinearities at ambient conditions.
Nonlinearity at the single-photon level is important in both fundamental research and applications of quantum optics. Strong single-photon nonlinearity is usually hard to achieve with a single atom coupled to a cavity mode. Unfortunately, stronger nonlinearity cannot be achieved by coupling more atoms straightforwardly because of the gradual homogeneity of the system energy levels. Here we propose two proposals to realize deeper photon blockade with the increase of the atom number with the help of quantum Zeno dynamics. The single-photon blockade that manifests single-photon nonlinearity is achieved with high single-photon efficiency and purity. We developed a hybrid method by partitioning the system states into two subsets with one computed via a master equation and the other via a non-Hermitian Hamiltonian. This method significantly reduces computational resource requirements and enables simulations of systems with up to thousands of atoms. The results show that our proposals are robust against the inhomogeneity of atom frequency and coupling strength, which is favorable in experiments.
Controlling light photon-by-photon is central to quantum optics. At a fundamental level, photon interactions are mediated by their coupling to atoms, and ultimate control requires deterministic light-matter interfacing of single photons to single atoms. Extending this paradigm to radiatively couple multiple individual atoms in a deterministic and scalable manner opens the arena of many-body quantum optics. Here, we realize such a setting by coherently coupling solid-state artificial atoms to a nanophotonic waveguide and demonstrate higher-order photon correlations that are controlled by the number of quantum emitters. We study the scaling of nonlinear photonic transport induced by emitter-photon scattering and demonstrate that adding a quantum emitter generates higher-order photon correlations. Specifically, we experimentally observe genuine three-photon correlations from a pair of collectively coupled emitters, while contributions from lower photon numbers are suppressed. In addition, we scale to three resonant quantum emitters coupled to the waveguide. These advancements demonstrate the onset of many-body quantum optics in waveguide quantum electrodynamics, enabling new photonic quantum simulators, the creation of many-body entangled states, and the exploration of novel quantum phase transitions.
Analogous to Coulomb blockade for electrons, photon blockade is a key quantum optical effect in which the presence of one photon prevents the transmission of subsequent ones through a nonlinear medium. Beyond its fundamental interest, photon and multi-photon blockade are actively studied as mechanisms for generating technologically-relevant quantum states of light. Although photon blockade typically requires achieving strong light-matter coupling, increasing the number of atoms fails to enhance antibunching. Here, we analyze the optical transmission properties of a quantum resonator that embeds a two-photon-coupled ensemble of emitters, combining an approximate analytical approach with full quantum numerical simulations. We show that when light and matter are coupled via a two-photon interaction, both single- and multi-photon blockade can benefit from a collective enhancement. We propose different driving schemes in which the second or third-order correlation functions are strongly suppressed with increasing atom number. Differently from established methods, this collective enhancement of non-classical properties occurs with unitary transmission and is ultimately constrained only by decoherence. This demonstrates that collective two-photon couplings are a powerful mechanism for realizing photon blockade even in platforms where individual strong coupling is not achievable.
The achievement of sufficiently fast interactions between two optical fields at the few-photon level would provide a key enabler for a broad range of quantum technologies. One critical hurdle in this endeavor is the lack of a comprehensive quantum theory of the generation of nonlinearities by ensembles of emitters. Distinct approaches applicable to different regimes have yielded important insights: i) a semiclassical approach reveals that, for many-photon coherent fields, the contributions of independent emitters add independently allowing ensembles to produce strong optical nonlinearities via EIT; ii) a quantum analysis has shown that in the few-photon regime collective coupling effects prevent ensembles from inducing these strong nonlinearities. Rather surprisingly, experimental results with around twenty photons are in line with the semi-classical predictions. Theoretical analysis has been fragmented due to the difficulty of treating nonlinear many-body quantum systems. Here we are able to solve this problem by constructing a powerful theory of the generation of optical nonlinearities by single emitters and ensembles. The key to this construction is the application of perturbation theory to perturbations generated by subsystems. This theory reveals critical properties of ensembles that have long been obscure. The most remarkable of these is the discovery that quantum effects prevent ensembles generating single-photon nonlinearities only within the rotating-wave regime; outside this regime single-photon nonlinearities scale as the number of emitters. The theory we present here also provides an efficient way to calculate nonlinearities for arbitrary multi-level driving schemes, and we expect that it will prove a powerful foundation for further advances in this area.