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:1701.01471 · Physical Review Letters

Subradiance via Entanglement in Atoms with Several Independent Decay Channels

Martin Hebenstreit, Barbara Kraus, Laurin Ostermann, Helmut Ritsch

Published Apr 7, 2017• 61 citations
arXivHTMLPDF

Abstract

Spontaneous emission of atoms in free space is modified by the presence of other atoms in close vicinity inducing collective super- and subradiance. For two nearby atoms with a single decay channel the entangled antisymmetric superposition state of the two single excited states will not decay spontaneously. No such excited two-atom dark state exists, if the excited state has two independent optical decay channels of different frequencies or polarizations. However, we show that for an excited atomic state with N-1 independent spontaneous decay channels one can find a highly entangled N-particle dark state, which completely decouples from the vacuum radiation field. It does not decay spontaneously, nor will it absorb resonant laser light. Mathematically, we see that this state is the only such state orthogonal to the subspace spanned by the atomic ground states. Moreover, by means of generic numerical examples we demonstrate that the subradiant behavior largely survives at finite atomic distances including dipole-dipole interactions.

DOI
10.1103/physrevlett.118.143602

Related papers

Subradiance in multiply excited states of dipole-coupled V-type atoms

Raphael Holzinger, Laurin Ostermann, Helmut Ritsch

We generalize the theoretical modeling of collective atomic super- and subradiance to the multilevel case including spontaneous emission from several excited states towards a common ground state. We show that in a closely packed ensemble of N atoms with N –1 distinct excited states each, one can find a new class of non-radiating dark states, which allows for long-term storage of N –1 photonic excitations. Via dipole-dipole coupling only a single atom in the ground state is sufficient in order to suppress the decay of all N –1 other atoms. By means of some generic geometric configurations, like a triangle of V-type atoms or a chain of atoms with a transition, we study such subradiance including dipole-dipole interactions and show that even at finite distances long lifetimes can be observed. While generally hard to prepare deterministically, we identify various possibilities for a probabilistic preparation via a phase-controlled laser pump and decay.

arXiv:1905.01483•Europhysics Letters (EPL)•Jan 30, 2020•7 citations

Engineering of spontaneous emission in free space via conditional measurements

Manuel Bojer, Lukas Götzendörfer, Romain Bachelard +1 more

We study the collective spontaneous emission of three identical two-level atoms initially prepared in the excited states by measuring Glauber's third-order photon correlation function. Assuming two atoms at subwavelength distance from each other such that they are subject to the dipole-dipole interaction while the third one is located several wavelengths away, we observe super- and subradiant decay alike, depending on the direction of observation. Unlike the case where no remote atom is introduced or no conditional measurements are performed, the spontaneous emission behavior of the conditioned three-atom system is strongly modified, i.e., differing from the single-atom and the canonical two-atom configuration. The conditional measurements associated with the three-photon correlation function in combination with the dipole-dipole interaction between the adjacent atoms lead to quantum interference among the different decay channels allowing one to engineer the spontaneous emission in space and time.

arXiv:2204.02049•Physical Review Research•Oct 11, 2022•3 citations

Collective spontaneous emission of two entangled atoms near an oscillating mirror

Marta Reina, Michelangelo Domina, Alessandro Ferreri +4 more

We consider the cooperative spontaneous emission of a system of two identical atoms interacting with the electromagnetic field in the vacuum state and in the presence of an oscillating mirror. We assume that the two atoms, one in the ground state and the other in the excited state, are prepared in a correlated (symmetric or antisymmetric) Bell-type state. We also suppose that the perfectly reflecting plate oscillates adiabatically, with the field modes satisfying the boundary conditions at the mirror surface at any given instant, so that the time dependence of the interaction Hamiltonian is entirely enclosed in the instantaneous atom-wall distance. Using time-dependent perturbation theory, we investigate the spectrum of the radiation emitted by the two-atom system, showing how the oscillation of the boundary modifies the features of the emitted spectrum, which exhibits two lateral peaks not present in the case of a static boundary. We also evaluate the transition rate to the collective ground state of the two-atom system in both cases of the superradiant (symmetric) and subradiant (antisymmetric) state. We show that it is modulated in time and that the presence of the oscillating mirror can enhance or inhibit the decay rate compared to the case of atoms in vacuum space or near a static boundary. Our results thus suggest that a dynamical (i.e., time-modulated) environment can offer further possibilities to control and manipulate radiative processes of atoms or molecules nearby, such as the cooperative decay, and strongly indicate a similar possibility for other radiative processes, for example, the resonance interaction and the energy transfer between atoms or molecules.

arXiv:2010.03215•Physical Review A•Mar 22, 2021•4 citations

Tuning the collective decay of two entangled emitters by means of a nearby surface

R Palacino, Roberto Passante, L Rizzuto +2 more

Abstract We consider the radiative properties of a system of two identical correlated atoms interacting with the electromagnetic field in its vacuum state in the presence of a generic dielectric environment. We suppose that the two emitters are prepared in a symmetric or antisymmetric superposition of one ground state and one excited state and we evaluate the transition rate to the collective ground state, showing distinctive cooperative radiative features. Using a macroscopic quantum electrodynamics approach to describe the electromagnetic field, we first obtain an analytical expression for the decay rate of the two entangled two-level atoms in terms of the Green’s tensor of the generic external environment. We then investigate the emission process when both atoms are in free space and, subsequently, when a perfectly reflecting mirror is present, showing how the boundary affects the physical features of the superradiant and subradiant emission by the two coupled emitters. The possibility to control and tailor radiative processes is also discussed.

arXiv:1704.08594•Journal of Physics B Atomic Molecular and Optical Physics•May 31, 2017•21 citations

Cooperative spontaneous emission from indistinguishable atoms in arbitrary motional quantum states

François Damanet, Daniel Braun, John Martin

We investigate superradiance and subradiance of indistinguishable atoms with quantized motional states, starting with an initial total state that factorizes over the internal and external degrees of freedom of the atoms. Due to the permutational symmetry of the motional state, the cooperative spontaneous emission, governed by a recently derived master equation [F. Damanet et al., Phys. Rev. A 93, 022124 (2016)], depends only on two decay rates $\ensuremath{\gamma}$ and ${\ensuremath{\gamma}}_{0}$ and a single parameter ${\mathrm{\ensuremath{\Delta}}}_{\mathrm{dd}}$ describing the dipole-dipole shifts. We solve the dynamics exactly for $N=2$ atoms, numerically for up to 30 atoms, and obtain the large-$N$ limit by a mean-field approach. We find that there is a critical difference ${\ensuremath{\gamma}}_{0}\ensuremath{-}\ensuremath{\gamma}$ that depends on $N$ beyond which superradiance is lost. We show that exact nontrivial dark states (i.e., states other than the ground state with vanishing spontaneous emission) only exist for $\ensuremath{\gamma}={\ensuremath{\gamma}}_{0}$ and that those states (dark when $\ensuremath{\gamma}={\ensuremath{\gamma}}_{0}$) are subradiant when $\ensuremath{\gamma}<{\ensuremath{\gamma}}_{0}$.

arXiv:1606.05102•Physical Review A•Sep 21, 2016•29 citations

Single-Photon Superradiance and Subradiance as Collective Emission from Symmetric and Anti-Symmetric States

N. Piovella, Stefano Olivares

Recent works have shown that collective single photon spontaneous emission from an ensemble of N resonant two-level atoms is a rich field of study. Superradiance describes emission from a completely symmetric state of N atoms, with a single excited atom prepared with a given phase, for instance imprinted by an external laser. Instead, subradiance is associated with the emission from the remaining N−1 asymmetric states, with a collective decay rate less than the single-atom value. Here, we discuss the properties of the orthonormal basis of symmetric and asymmetric states and the entanglement properties of superradiant and subradiant states.

arXiv:2307.14667•Symmetry•Sep 25, 2023•1 citation
Spontaneous emission of atoms in free space is modified by the presence of other atoms in close vicinity inducing collective super- and subradiance. For two nearby atoms with a single decay channel the entangled antisymmetric superposition state of the two single excited states will not decay spontaneously. No such excited two-atom dark state exists, if the excited state has two independent optical decay channels of different frequencies or polarizations. However, we show that for an excited atomic state with N-1 independent spontaneous decay channels one can find a highly entangled N-particle dark state, which completely decouples from the vacuum radiation field. It does not decay spontaneously, nor will it absorb resonant laser light. Mathematically, we see that this state is the only such state orthogonal to the subspace spanned by the atomic ground states. Moreover, by means of generic numerical examples we demonstrate that the subradiant behavior largely survives at finite atomic distances including dipole-dipole interactions.
We generalize the theoretical modeling of collective atomic super- and subradiance to the multilevel case including spontaneous emission from several excited states towards a common ground state. We show that in a closely packed ensemble of N atoms with N –1 distinct excited states each, one can find a new class of non-radiating dark states, which allows for long-term storage of N –1 photonic excitations. Via dipole-dipole coupling only a single atom in the ground state is sufficient in order to suppress the decay of all N –1 other atoms. By means of some generic geometric configurations, like a triangle of V-type atoms or a chain of atoms with a transition, we study such subradiance including dipole-dipole interactions and show that even at finite distances long lifetimes can be observed. While generally hard to prepare deterministically, we identify various possibilities for a probabilistic preparation via a phase-controlled laser pump and decay.
We study the collective spontaneous emission of three identical two-level atoms initially prepared in the excited states by measuring Glauber's third-order photon correlation function. Assuming two atoms at subwavelength distance from each other such that they are subject to the dipole-dipole interaction while the third one is located several wavelengths away, we observe super- and subradiant decay alike, depending on the direction of observation. Unlike the case where no remote atom is introduced or no conditional measurements are performed, the spontaneous emission behavior of the conditioned three-atom system is strongly modified, i.e., differing from the single-atom and the canonical two-atom configuration. The conditional measurements associated with the three-photon correlation function in combination with the dipole-dipole interaction between the adjacent atoms lead to quantum interference among the different decay channels allowing one to engineer the spontaneous emission in space and time.
We consider the cooperative spontaneous emission of a system of two identical atoms interacting with the electromagnetic field in the vacuum state and in the presence of an oscillating mirror. We assume that the two atoms, one in the ground state and the other in the excited state, are prepared in a correlated (symmetric or antisymmetric) Bell-type state. We also suppose that the perfectly reflecting plate oscillates adiabatically, with the field modes satisfying the boundary conditions at the mirror surface at any given instant, so that the time dependence of the interaction Hamiltonian is entirely enclosed in the instantaneous atom-wall distance. Using time-dependent perturbation theory, we investigate the spectrum of the radiation emitted by the two-atom system, showing how the oscillation of the boundary modifies the features of the emitted spectrum, which exhibits two lateral peaks not present in the case of a static boundary. We also evaluate the transition rate to the collective ground state of the two-atom system in both cases of the superradiant (symmetric) and subradiant (antisymmetric) state. We show that it is modulated in time and that the presence of the oscillating mirror can enhance or inhibit the decay rate compared to the case of atoms in vacuum space or near a static boundary. Our results thus suggest that a dynamical (i.e., time-modulated) environment can offer further possibilities to control and manipulate radiative processes of atoms or molecules nearby, such as the cooperative decay, and strongly indicate a similar possibility for other radiative processes, for example, the resonance interaction and the energy transfer between atoms or molecules.
Abstract We consider the radiative properties of a system of two identical correlated atoms interacting with the electromagnetic field in its vacuum state in the presence of a generic dielectric environment. We suppose that the two emitters are prepared in a symmetric or antisymmetric superposition of one ground state and one excited state and we evaluate the transition rate to the collective ground state, showing distinctive cooperative radiative features. Using a macroscopic quantum electrodynamics approach to describe the electromagnetic field, we first obtain an analytical expression for the decay rate of the two entangled two-level atoms in terms of the Green’s tensor of the generic external environment. We then investigate the emission process when both atoms are in free space and, subsequently, when a perfectly reflecting mirror is present, showing how the boundary affects the physical features of the superradiant and subradiant emission by the two coupled emitters. The possibility to control and tailor radiative processes is also discussed.
We investigate superradiance and subradiance of indistinguishable atoms with quantized motional states, starting with an initial total state that factorizes over the internal and external degrees of freedom of the atoms. Due to the permutational symmetry of the motional state, the cooperative spontaneous emission, governed by a recently derived master equation [F. Damanet et al., Phys. Rev. A 93, 022124 (2016)], depends only on two decay rates $\ensuremath{\gamma}$ and ${\ensuremath{\gamma}}_{0}$ and a single parameter ${\mathrm{\ensuremath{\Delta}}}_{\mathrm{dd}}$ describing the dipole-dipole shifts. We solve the dynamics exactly for N=2N=2N=2 atoms, numerically for up to 30 atoms, and obtain the large-NNN limit by a mean-field approach. We find that there is a critical difference ${\ensuremath{\gamma}}_{0}\ensuremath{-}\ensuremath{\gamma}$ that depends on NNN beyond which superradiance is lost. We show that exact nontrivial dark states (i.e., states other than the ground state with vanishing spontaneous emission) only exist for $\ensuremath{\gamma}={\ensuremath{\gamma}}_{0}$ and that those states (dark when $\ensuremath{\gamma}={\ensuremath{\gamma}}_{0}$) are subradiant when $\ensuremath{\gamma}<{\ensuremath{\gamma}}_{0}$.
Recent works have shown that collective single photon spontaneous emission from an ensemble of N resonant two-level atoms is a rich field of study. Superradiance describes emission from a completely symmetric state of N atoms, with a single excited atom prepared with a given phase, for instance imprinted by an external laser. Instead, subradiance is associated with the emission from the remaining N−1 asymmetric states, with a collective decay rate less than the single-atom value. Here, we discuss the properties of the orthonormal basis of symmetric and asymmetric states and the entanglement properties of superradiant and subradiant states.