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:1702.08075 · Journal of Physics Communications

Entanglement between living bacteria and quantized light witnessed by Rabi splitting

Chiara Marletto, David M. Coles, Tristan Farrow, Vlatko Vedral

Published Sep 18, 2018• 58 citations
arXivHTMLPDF

Abstract

We model recent experiments on living sulphur bacteria interacting with quantised light, using the Dicke model. Our analysis shows that the strong coupling between the bacteria and the light, when both are treated quantum-mechanically, indicates that in those experiments there is entanglement between the bacteria (modelled as dipoles) and the quantised light (modelled as a single quantum harmonic oscillator). The existence of lower polariton branch due to the vacuum Rabi splitting, measured in those experiments for a range of different parameters, ensures the negativity of energy (with respect to the lowest energy of separable states), thus acting as an entanglement witness.

DOI
10.1088/2399-6528/aae224

Related papers

Probing quantum features of photosynthetic organisms

Tanjung Krisnanda, Chiara Marletto, Vlatko Vedral +2 more

Abstract Recent experiments have demonstrated strong coupling between living bacteria and light. Here we propose a scheme capable of revealing non-classical features of the bacteria (quantum discord of light–bacteria correlations) without exact modelling of the organisms and their interactions with external world. The scheme puts the bacteria in a role of mediators of quantum entanglement between otherwise non-interacting probing light modes. We then propose a plausible model of this experiment, using recently achieved parameters, demonstrating the feasibility of the scheme. Within this model we find that the steady-state entanglement between the probes, which does not depend on the initial conditions, is accompanied by entanglement between the probes and bacteria, and provides independent evidence of the strong coupling between them.

arXiv:1711.06485•npj Quantum Information•Nov 15, 2018•32 citations

Manipulating light–matter interaction into strong coupling regime for photon entanglement in plasmonic lattices

Zhihang Wang, Lingyao Li, Shibo Wei +6 more

Enhancing light–matter interaction into the strong coupling regime attracts tremendous attention in both theory and experiment, which presents essential significance in research from nano-optics to quantum information. In this work, the entanglement effect is observed in the photons emitted from a plasmonic lattice as the coherent light–matter interaction occurs into the strong coupling regime with a Rabi splitting of 93.4 meV. A full quantum mechanical treatment based on the number state representation is established to reveal the underlying physics of the strong coupling phenomenon, especially the femtosecond dynamics of energy exchange and damping. The entangled split states display oscillating concurrence and negative Wigner quasiprobability distribution function, which demonstrates that this designed plasmonic lattice system can serve as an on-demand entangled photon source for quantum information.

Journal of Applied Physics•Feb 8, 2023•10 citations

Vacuum Rabi splitting as a manifestation of virtual two-mode squeezing: Extracting the squeezing parameters from frequency shifts

Karol Gietka

Vacuum Rabi splitting relies on symmetrical splitting of the common resonance frequency of atoms and the cavity in which the atoms reside. In this work, we argue that vacuum Rabi splitting is a manifestation of virtual light-matter two-mode squeezing. We establish a connection between squeezing parameters of virtual excitations and frequency shifts of the physical modes, which allows to nondestructively extract the squeezing parameters without measuring correlations. To this end, we use the mapping between the Dicke model and two interacting harmonic oscillators, which we analyze in the framework of bare and physical modes.

arXiv:2403.12177•Physical Review A•Dec 6, 2024•5 citations

Oscillator model for vacuum Rabi splitting in microcavities

S. Rudin, T. L. Reinecke

The vacuum-field Rabi splitting of an optical mode in a cavity interacting with a system of N excitations (atomic or electronic) represented by harmonic oscillators is obtained quantum mechanically both without and with coupling to dissipation. The optical lineshapes and the scaling of the Rabi splitting with the number of oscillators and its dependence on the damping parameters are given. Corresponding results are given for a classical treatment of the oscillators, and it is shown that to the leading order in the dissipation, the quantum mechanical results for absorption are the same as the classical ones.

Physical review. B, Condensed matter•Apr 15, 1999•97 citations

Quantum entanglement between the electron clouds of nucleic acids in DNA

Elisabeth Rieper, Janet Anders, Vlatko Vedral

We model the electron clouds of nucleic acids in DNA as a chain of coupled quantum harmonic oscillators with dipole-dipole interaction between nearest neighbours resulting in a van der Waals type bonding. Crucial parameters in our model are the distances between the acids and the coupling between them, which we estimate from numerical simulations [1]. We show that for realistic parameters nearest neighbour entanglement is present even at room temperature. We quantify the amount of entanglement in terms of negativity and single base von Neumann entropy. We find that the strength of the single base von Neumann entropy depends on the neighbouring sites, thus questioning the notion of treating single bases as logically independent units. We derive an analytical expression for the binding energy of the coupled chain in terms of entanglement and show the connection between entanglement and correlation energy, a quantity commonly used in quantum chemistry.

arXiv:1006.4053•Jun 21, 2010•33 citations

Quantum mechanical solution to spectral lineshape in strongly-coupled atom–nanocavity system

Jian Zeng, Zhiyuan Li

The strongly coupled system composed of atoms, molecules, molecule aggregates, and semiconductor quantum dots embedded within an optical microcavity/nanocavity with high quality factor and/or low modal volume has become an excellent platform to study cavity quantum electrodynamics (CQED), where a prominent quantum effect called Rabi splitting can occur due to strong interaction of cavity-mode single-photon with the two-level atomic states. In this paper, we build a new quantum model that can describe the optical response of the strongly-coupled system under the action of an external probing light and the spectral lineshape. We take the Hamiltonian for the strongly-coupled photon–atom system as the unperturbed Hamiltonian H 0 and the interaction Hamiltonian of the probe light upon the coupled-system quantum states as the perturbed Hamiltonian V . The theory yields a double Lorentzian lineshape for the permittivity function, which agrees well with experimental observation of Rabi splitting in terms of spectral splitting. This quantum theory will pave the way to construct a complete understanding for the microscopic strongly-coupled system that will become an important element for quantum information processing, nano-optical integrated circuits, and polariton chemistry.

Chinese Physics B•Dec 8, 2021•1 citation
We model recent experiments on living sulphur bacteria interacting with quantised light, using the Dicke model. Our analysis shows that the strong coupling between the bacteria and the light, when both are treated quantum-mechanically, indicates that in those experiments there is entanglement between the bacteria (modelled as dipoles) and the quantised light (modelled as a single quantum harmonic oscillator). The existence of lower polariton branch due to the vacuum Rabi splitting, measured in those experiments for a range of different parameters, ensures the negativity of energy (with respect to the lowest energy of separable states), thus acting as an entanglement witness.
Abstract Recent experiments have demonstrated strong coupling between living bacteria and light. Here we propose a scheme capable of revealing non-classical features of the bacteria (quantum discord of light–bacteria correlations) without exact modelling of the organisms and their interactions with external world. The scheme puts the bacteria in a role of mediators of quantum entanglement between otherwise non-interacting probing light modes. We then propose a plausible model of this experiment, using recently achieved parameters, demonstrating the feasibility of the scheme. Within this model we find that the steady-state entanglement between the probes, which does not depend on the initial conditions, is accompanied by entanglement between the probes and bacteria, and provides independent evidence of the strong coupling between them.
Enhancing light–matter interaction into the strong coupling regime attracts tremendous attention in both theory and experiment, which presents essential significance in research from nano-optics to quantum information. In this work, the entanglement effect is observed in the photons emitted from a plasmonic lattice as the coherent light–matter interaction occurs into the strong coupling regime with a Rabi splitting of 93.4 meV. A full quantum mechanical treatment based on the number state representation is established to reveal the underlying physics of the strong coupling phenomenon, especially the femtosecond dynamics of energy exchange and damping. The entangled split states display oscillating concurrence and negative Wigner quasiprobability distribution function, which demonstrates that this designed plasmonic lattice system can serve as an on-demand entangled photon source for quantum information.
Vacuum Rabi splitting relies on symmetrical splitting of the common resonance frequency of atoms and the cavity in which the atoms reside. In this work, we argue that vacuum Rabi splitting is a manifestation of virtual light-matter two-mode squeezing. We establish a connection between squeezing parameters of virtual excitations and frequency shifts of the physical modes, which allows to nondestructively extract the squeezing parameters without measuring correlations. To this end, we use the mapping between the Dicke model and two interacting harmonic oscillators, which we analyze in the framework of bare and physical modes.
The vacuum-field Rabi splitting of an optical mode in a cavity interacting with a system of N excitations (atomic or electronic) represented by harmonic oscillators is obtained quantum mechanically both without and with coupling to dissipation. The optical lineshapes and the scaling of the Rabi splitting with the number of oscillators and its dependence on the damping parameters are given. Corresponding results are given for a classical treatment of the oscillators, and it is shown that to the leading order in the dissipation, the quantum mechanical results for absorption are the same as the classical ones.
We model the electron clouds of nucleic acids in DNA as a chain of coupled quantum harmonic oscillators with dipole-dipole interaction between nearest neighbours resulting in a van der Waals type bonding. Crucial parameters in our model are the distances between the acids and the coupling between them, which we estimate from numerical simulations [1]. We show that for realistic parameters nearest neighbour entanglement is present even at room temperature. We quantify the amount of entanglement in terms of negativity and single base von Neumann entropy. We find that the strength of the single base von Neumann entropy depends on the neighbouring sites, thus questioning the notion of treating single bases as logically independent units. We derive an analytical expression for the binding energy of the coupled chain in terms of entanglement and show the connection between entanglement and correlation energy, a quantity commonly used in quantum chemistry.
The strongly coupled system composed of atoms, molecules, molecule aggregates, and semiconductor quantum dots embedded within an optical microcavity/nanocavity with high quality factor and/or low modal volume has become an excellent platform to study cavity quantum electrodynamics (CQED), where a prominent quantum effect called Rabi splitting can occur due to strong interaction of cavity-mode single-photon with the two-level atomic states. In this paper, we build a new quantum model that can describe the optical response of the strongly-coupled system under the action of an external probing light and the spectral lineshape. We take the Hamiltonian for the strongly-coupled photon–atom system as the unperturbed Hamiltonian H 0 and the interaction Hamiltonian of the probe light upon the coupled-system quantum states as the perturbed Hamiltonian V . The theory yields a double Lorentzian lineshape for the permittivity function, which agrees well with experimental observation of Rabi splitting in terms of spectral splitting. This quantum theory will pave the way to construct a complete understanding for the microscopic strongly-coupled system that will become an important element for quantum information processing, nano-optical integrated circuits, and polariton chemistry.