Collective effects, such as superradiance and subradiance are central to emerging quantum technologies -- from sensing to energy storage -- and play an important role in light-harvesting. These effects enhance or suppress rates of dynamic processes (absorption, emission, and transfer) due to the formation of symmetric or antisymmetric collective states. However, collective effects in different contexts -- absorption, emission, and transfer -- have often been defined disparately, especially across different communities, leading to results that are not immediately transferable between different contexts. Here, we describe all three types of collective effects using a common Dicke framework that resolves the apparent discrepancies between different approaches. It allows us to generalise previously known collective effects involving spins into new ones involving aggregates of harmonic oscillators or other degrees of freedom. It also explains how collective effects can be engineered to be robust against both disorder and noise, paving the way for more resilient quantum devices.Collective effects, such as superradiance and subradiance are central to emerging quantum technologies -- from sensing to energy storage -- and play an important role in light-harvesting. These effects enhance or suppress rates of dynamic processes (absorption, emission, and transfer) due to the formation of symmetric or antisymmetric collective states. However, collective effects in different contexts -- absorption, emission, and transfer -- have often been defined disparately, especially across different communities, leading to results that are not immediately transferable between different contexts. Here, we describe all three types of collective effects using a common Dicke framework that resolves the apparent discrepancies between different approaches. It allows us to generalise previously known collective effects involving spins into new ones involving aggregates of harmonic oscillators or other degrees of freedom. It also explains how collective effects can be engineered to be robust against both disorder and noise, paving the way for more resilient quantum devices.

quant-pharXiv:2511.22335Nov 28, 20250 citations

Ensembles and Effects

Günther Ludwig

Springer eBooksJan 1, 19831 citation

Quenching the collective effects on the two-photon correlation from two double-Raman atoms

C. H. Raymond Ooi

We obtain an analytical expression for two-photon correlation ${G}^{(2)}$ from two atoms driven in a double-Raman (or $\ensuremath{\Lambda}$) configuration where collective effects such as superradiant, subradiant, and dipole-dipole interaction are included. It is found that the collective effects on the ${G}^{(2)}$ can be quenched to some extent by a resonant control laser field. The collective effects provide features via ${G}^{(2)}$ that enable the two atoms to be resolved at subwavelength separation. We also identify an effect in the double Raman scheme due to the collective effects and the control field, i.e., the Stokes and anti-Stokes frequencies are increased by fourfold.We obtain an analytical expression for two-photon correlation ${G}^{(2)}$ from two atoms driven in a double-Raman (or $\ensuremath{\Lambda}$) configuration where collective effects such as superradiant, subradiant, and dipole-dipole interaction are included. It is found that the collective effects on the ${G}^{(2)}$ can be quenched to some extent by a resonant control laser field. The collective effects provide features via ${G}^{(2)}$ that enable the two atoms to be resolved at subwavelength separation. We also identify an effect in the double Raman scheme due to the collective effects and the control field, i.e., the Stokes and anti-Stokes frequencies are increased by fourfold.

Physical Review AApr 26, 200712 citations

Collective Model

WORLD SCIENTIFIC eBooksMay 2, 20070 citations

Collective Model

WORLD SCIENTIFIC eBooksFeb 1, 20080 citations

The Dynamical Casimir Effect versus Collective Excitations in Atom Ensemble

Xue Zhang, Tai-Yu Zheng, Tian Tian +1 more

The Dynamical Casimir effect and collective excitations in atom ensemble are investigated in a non-stationary cavity. The results show that the dynamical Casimir effect leads to the collective excitations of atom ensemble due to absorption of the created photons. This remarkable feature indicates that the atom ensemble can serve as a detector for the process of photon production in a non-stationary cavity. Therefore by measuring the collective excitations of the atom ensemble, the dynamical Casimir effect can indirectly be verified.The Dynamical Casimir effect and collective excitations in atom ensemble are investigated in a non-stationary cavity. The results show that the dynamical Casimir effect leads to the collective excitations of atom ensemble due to absorption of the created photons. This remarkable feature indicates that the atom ensemble can serve as a detector for the process of photon production in a non-stationary cavity. Therefore by measuring the collective excitations of the atom ensemble, the dynamical Casimir effect can indirectly be verified.

Chinese Physics LettersJun 1, 20118 citations

We obtain an analytical expression for two-photon correlation

{G}^{(2)}

from two atoms driven in a double-Raman (or $\ensuremath{\Lambda}$) configuration where collective effects such as superradiant, subradiant, and dipole-dipole interaction are included. It is found that the collective effects on the

{G}^{(2)}

can be quenched to some extent by a resonant control laser field. The collective effects provide features via

{G}^{(2)}

that enable the two atoms to be resolved at subwavelength separation. We also identify an effect in the double Raman scheme due to the collective effects and the control field, i.e., the Stokes and anti-Stokes frequencies are increased by fourfold.