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

Laser Physics

Superradiance enhancement by bad-cavity resonator

Nikita E. Nefedkin, E. S. Andrianov, Alexander Pukhov, Alexey P. Vinogradov

Published May 11, 2017• 6 citations
Publisher

Abstract

Abstract In this work we consider the dynamics of an ensemble of two-level atoms that interact with finite-width resonator mode. The superradiant burst occurs under a wide range of parameters in such a system. However, if the initial phase distribution of dipole moments of N two-level atoms is random, not all atoms take part in the superradiant process, but only the part of them that results in the intensity of supperradiance I ∼ N α , where α < 2 . In this paper we investigate the dependence of the parameter α on the resonator mode decay rate. It is shown that there is a critical value of resonator mode decay rate that divides two different regimes of superradiance. If the decay rate is lower than the critical rate, superradiance demonstrates a multi-peak character and the number of dipoles forming superradiant burst increases while α grows from 1 to 2. When the decay rate is larger than the critical value there is a single-peak superradiant regime. The delay time dependence on N changes from power to logarithmic law at the critical decay rate. The existence of the optimal value of resonator decay rate can be used for superradiance enhancement by a resonator with finite losses.

DOI
10.1088/1555-6611/aa6f6d

Related papers

From Superradiance to Superabsorption: An Exact Treatment of Non-Markovian Cooperative Radiation

Ignacio González, Ángel Rivas

We investigate the emergence of cooperative radiation phenomena in ensembles of two-level atoms coupled to a lossy resonant cavity beyond the Markovian and mean-field approximations. By deriving a complete analytical solution for the two-emitter case and employing a numerically exact method for larger ensembles, we characterize the full transition from Markovian to non-Markovian collective dynamics for systems of up to $10^3$ emitters. Our results reveal three distinct regimes: a Markovian phase exhibiting the standard superradiant burst, a non-Markovian phase featuring spontaneous superabsorption of the emitted field, and a critical regime marked by pulsed collective emission. We show that the critical spectral width separating these behaviors increases monotonically with the number of emitters, demonstrating that environmental memory effects can be enhanced by cooperativity. Finally, we find that the superradiant scaling of the peak intensity progressively degrades with increasing system size, approaching a subquadratic law in the limit of a perfect cavity. In this regime, spontaneous superabsorption emerges as a distinct manifestation of non-Markovian cooperativity.

quant-pharXiv:2601.05989•Quantum•Jan 12, 2026•0 citations

Superradiance of non-interacting atoms

M. Bojer, Joachim von Zanthier

Fully-excited two-level atoms separated by less than the transition wavelength cooperatively emit light in a short burst, a phenomenon called superradiance by R. Dicke in 1954. The burst is characterized by a maximum intensity scaling with the square of the number of atoms $N$ and a temporal width reduced by $N$ compared to the single atom spontaneous decay time. Both effects are usually attributed to a synchronization of the electric dipole moments of the atoms occurring during the process of light emission. Contrary to this explanation, it was recently shown by use of a quantum path description that the peak intensity results from the quantum correlations among the atoms when occupying symmetric Dicke states. Here we investigate from this perspective the temporal evolution of the ensemble, starting in the small sample limit, i.e., when the atoms have mutual separations much smaller than the transition wavelength $λ$ and pass down the ladder of symmetric Dicke states. In addition, we explore the temporal evolution for the case of non-interacting atoms with mutual separations much larger than $λ$. We show that in this case a similar superradiant burst of the emitted radiation is observed if the quantum correlations of the atoms are generated by conditional photon measurements retaining the atomic ensemble within or close to the symmetric subspace.

arXiv:2206.14646•Jun 29, 2022•1 citation

Superradiance of two-component spatial inhomogeneous media

Andrey Andreev, Sergei Sheetlin

The two—component superradiative medium consists of two species of atoms with the different dipole moments of the quasi-resonant transitions. The atoms with the smaller dipole moment are initially in the excited state, while е atoms of the second type are initially in the ground state. In the initial stage of the superradiance dynamics the first component is amplifying one, the second component is resonantly absorbing. By varying the concentration of the resonantly absorbing atoms it is possible to increase the intensity of superradiance in the few order of magnitude with respect to the monocomponent medium of the amplifying atoms alone. Here we show that the variation in the distribution of the component densities enables us the additional possibilities in the control of the superradiance pulse parameters. The additional increase in the order of magnitude for the peak pulse intensity is obtained at the optimal distribution. The nature of such variation in the pulse profile and its intensity is due to the opportunity for the effective spatial mode selection in the spatial inhomogeneous media. We discuss the algorithms of е numerical solution and show that the enhanced accuracy methods can be developed in this case.

Izvestiya VUZ Applied Nonlinear Dynamics•Jan 1, 1997•0 citations

Eigenmode analysis of superradiance

Jamal T. Manassah

Previous numerical work on the spatiotemporal distributions of the atomic polarization and of the difference in levels population of a one-dimensional system of two-level atoms initially inverted strongly suggested that the dynamics of the slab atomic ensemble in the linear regime of superradiance may best be treated by an eigenmode analysis. This method proved effective in obtaining both the time dependence of the atomic polarization and the spectral distribution of the emitted radiation from the slab in a number of physically interesting problems in the linear regime. In the present paper, I use the eigenfunction expansion technique to reduce the Maxwell-Bloch system of partial differential equations into a system of coupled first-order ordinary differential equations whose solutions clearly detail the contributions of the different modes to the system dynamics in the nonlinear regime of superradiant emission. I compute also the delay in time of the peak of the superradiant burst and its magnitude as functions of the ratio of the longitudinal decay rate to the transverse decay rate of the system.

Physical Review A•May 12, 2014•14 citations

A Mini-Review: Cooperative Spontaneous Emission from Two- and Three-Level Atoms

Munkh-Uchral Bazarsan, Mend-Amar Lutsukh, Tuguldur Begzjav +1 more

In Dicke superradiance, N identical two-level atoms in a small volume share one collective excitation ladder, and the ensemble discharges in a delayed burst whose peak grows in accordance with N2 rather than N. Real emitters, however, usually have more than two levels. When such an ensemble radiates cooperatively, its multiple decay channels interact rather than simply add up. This mini-review covers recent work that solves this interaction exactly for three-level atoms. We first recall the two-level benchmark: its exact delay statistics, their Gumbel-distributed fluctuation, and the resulting 21.7% deficit of the ensemble-averaged peak below the semi-classical estimate. The master-equation framework developed by Agarwal and Cho, Kurnit and Gilmore, on which the three-level results rest, comes next. The main part surveys three published papers, one for each of the three dipole-allowed three-level configurations. In the cascade, two emission pulses are correlated through an inherited timing. In the shared-source configuration, two channels compete for one atomic reservoir; for equal rates, as shown by Holzinger et al., this competition produces an exactly uniform terminal distribution, as in a Pólya urn. In the shared-sink configuration, two dynamically independent groups of atoms merge exactly into a single collective burst of the combined ensemble. We call this superradiant synthesis.

Photonics•Sep 30, 2026•0 citations

Theory of Steady-State Superradiance

Minghui Xu

In this thesis, I describe the theoretical development of the superradiant laser, or laser in the extreme bad-cavity regime. In this regime, the cavity decay rate is much greater than the atomic dynamics. The atoms emit photons into the cavity mode superradiantly in steady state. We develop group-theoretic methods that enable us to exactly solve mesoscopic systems with hundreds of atoms. We demonstrate the synchronization of atomic dipoles in steady-state superradiance. With this synchronized system, we propose conditional Ramsey spectroscopy which allows us to observe Ramsey fringes indefinitely, even in the presence of atomic decoherence. Furthermore, we explore manifestations of synchronization in the quantum realm with two superradiant atomic ensembles. We show that two such ensembles exhibit a dynamical phase transition from two disparate oscillators to quantum phase-locked dynamics. Finally, we study the mechanical eect of the light-atom interaction in the steady-state superradiance. We find efficient many-body cooling of atoms. The work described in this thesis lays the theoretical foundation for the superradiant laser and for a potential future of active optical frequency standards.

•Jan 1, 2016•3 citations
Abstract In this work we consider the dynamics of an ensemble of two-level atoms that interact with finite-width resonator mode. The superradiant burst occurs under a wide range of parameters in such a system. However, if the initial phase distribution of dipole moments of N two-level atoms is random, not all atoms take part in the superradiant process, but only the part of them that results in the intensity of supperradiance I ∼ N α , where α < 2 . In this paper we investigate the dependence of the parameter α on the resonator mode decay rate. It is shown that there is a critical value of resonator mode decay rate that divides two different regimes of superradiance. If the decay rate is lower than the critical rate, superradiance demonstrates a multi-peak character and the number of dipoles forming superradiant burst increases while α grows from 1 to 2. When the decay rate is larger than the critical value there is a single-peak superradiant regime. The delay time dependence on N changes from power to logarithmic law at the critical decay rate. The existence of the optimal value of resonator decay rate can be used for superradiance enhancement by a resonator with finite losses.
We investigate the emergence of cooperative radiation phenomena in ensembles of two-level atoms coupled to a lossy resonant cavity beyond the Markovian and mean-field approximations. By deriving a complete analytical solution for the two-emitter case and employing a numerically exact method for larger ensembles, we characterize the full transition from Markovian to non-Markovian collective dynamics for systems of up to 10310^3103 emitters. Our results reveal three distinct regimes: a Markovian phase exhibiting the standard superradiant burst, a non-Markovian phase featuring spontaneous superabsorption of the emitted field, and a critical regime marked by pulsed collective emission. We show that the critical spectral width separating these behaviors increases monotonically with the number of emitters, demonstrating that environmental memory effects can be enhanced by cooperativity. Finally, we find that the superradiant scaling of the peak intensity progressively degrades with increasing system size, approaching a subquadratic law in the limit of a perfect cavity. In this regime, spontaneous superabsorption emerges as a distinct manifestation of non-Markovian cooperativity.
Fully-excited two-level atoms separated by less than the transition wavelength cooperatively emit light in a short burst, a phenomenon called superradiance by R. Dicke in 1954. The burst is characterized by a maximum intensity scaling with the square of the number of atoms NNN and a temporal width reduced by NNN compared to the single atom spontaneous decay time. Both effects are usually attributed to a synchronization of the electric dipole moments of the atoms occurring during the process of light emission. Contrary to this explanation, it was recently shown by use of a quantum path description that the peak intensity results from the quantum correlations among the atoms when occupying symmetric Dicke states. Here we investigate from this perspective the temporal evolution of the ensemble, starting in the small sample limit, i.e., when the atoms have mutual separations much smaller than the transition wavelength λλλ and pass down the ladder of symmetric Dicke states. In addition, we explore the temporal evolution for the case of non-interacting atoms with mutual separations much larger than λλλ. We show that in this case a similar superradiant burst of the emitted radiation is observed if the quantum correlations of the atoms are generated by conditional photon measurements retaining the atomic ensemble within or close to the symmetric subspace.
The two—component superradiative medium consists of two species of atoms with the different dipole moments of the quasi-resonant transitions. The atoms with the smaller dipole moment are initially in the excited state, while е atoms of the second type are initially in the ground state. In the initial stage of the superradiance dynamics the first component is amplifying one, the second component is resonantly absorbing. By varying the concentration of the resonantly absorbing atoms it is possible to increase the intensity of superradiance in the few order of magnitude with respect to the monocomponent medium of the amplifying atoms alone. Here we show that the variation in the distribution of the component densities enables us the additional possibilities in the control of the superradiance pulse parameters. The additional increase in the order of magnitude for the peak pulse intensity is obtained at the optimal distribution. The nature of such variation in the pulse profile and its intensity is due to the opportunity for the effective spatial mode selection in the spatial inhomogeneous media. We discuss the algorithms of е numerical solution and show that the enhanced accuracy methods can be developed in this case.
Previous numerical work on the spatiotemporal distributions of the atomic polarization and of the difference in levels population of a one-dimensional system of two-level atoms initially inverted strongly suggested that the dynamics of the slab atomic ensemble in the linear regime of superradiance may best be treated by an eigenmode analysis. This method proved effective in obtaining both the time dependence of the atomic polarization and the spectral distribution of the emitted radiation from the slab in a number of physically interesting problems in the linear regime. In the present paper, I use the eigenfunction expansion technique to reduce the Maxwell-Bloch system of partial differential equations into a system of coupled first-order ordinary differential equations whose solutions clearly detail the contributions of the different modes to the system dynamics in the nonlinear regime of superradiant emission. I compute also the delay in time of the peak of the superradiant burst and its magnitude as functions of the ratio of the longitudinal decay rate to the transverse decay rate of the system.
In Dicke superradiance, N identical two-level atoms in a small volume share one collective excitation ladder, and the ensemble discharges in a delayed burst whose peak grows in accordance with N2 rather than N. Real emitters, however, usually have more than two levels. When such an ensemble radiates cooperatively, its multiple decay channels interact rather than simply add up. This mini-review covers recent work that solves this interaction exactly for three-level atoms. We first recall the two-level benchmark: its exact delay statistics, their Gumbel-distributed fluctuation, and the resulting 21.7% deficit of the ensemble-averaged peak below the semi-classical estimate. The master-equation framework developed by Agarwal and Cho, Kurnit and Gilmore, on which the three-level results rest, comes next. The main part surveys three published papers, one for each of the three dipole-allowed three-level configurations. In the cascade, two emission pulses are correlated through an inherited timing. In the shared-source configuration, two channels compete for one atomic reservoir; for equal rates, as shown by Holzinger et al., this competition produces an exactly uniform terminal distribution, as in a Pólya urn. In the shared-sink configuration, two dynamically independent groups of atoms merge exactly into a single collective burst of the combined ensemble. We call this superradiant synthesis.
In this thesis, I describe the theoretical development of the superradiant laser, or laser in the extreme bad-cavity regime. In this regime, the cavity decay rate is much greater than the atomic dynamics. The atoms emit photons into the cavity mode superradiantly in steady state. We develop group-theoretic methods that enable us to exactly solve mesoscopic systems with hundreds of atoms. We demonstrate the synchronization of atomic dipoles in steady-state superradiance. With this synchronized system, we propose conditional Ramsey spectroscopy which allows us to observe Ramsey fringes indefinitely, even in the presence of atomic decoherence. Furthermore, we explore manifestations of synchronization in the quantum realm with two superradiant atomic ensembles. We show that two such ensembles exhibit a dynamical phase transition from two disparate oscillators to quantum phase-locked dynamics. Finally, we study the mechanical eect of the light-atom interaction in the steady-state superradiance. We find efficient many-body cooling of atoms. The work described in this thesis lays the theoretical foundation for the superradiant laser and for a potential future of active optical frequency standards.