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

Journal of Physics B Atomic Molecular and Optical Physics

Cavity quantum electrodynamics with a single molecule: Purcell enhancement, strong coupling and single-photon nonlinearity

Daqing Wang

Published Apr 12, 2021• 16 citations
Publisher

Abstract

Abstract Control of light–matter coupling at the quantum level is an enabling technique for many emerging quantum technologies. This tutorial describes recent advances in achieving efficient coupling of light with a single molecule using an optical Fabry–Perot microcavity. We demonstrate that the efficient cavity-molecule coupling converts the molecule to an effective two-level system. In this regime, a single molecule can act as a nearly perfect reflecting mirror and exhibits optical nonlinearity at the ultimate level of single photons.

DOI
10.1088/1361-6455/abf6e1

Related papers

Single-Molecule Vacuum Rabi Splitting: Four-Wave Mixing and Optical Switching at the Single-Photon Level

André Pscherer, Manuel Meierhofer, Daqing Wang +5 more

A single quantum emitter can possess a very strong intrinsic nonlinearity, but its overall promise for nonlinear effects is hampered by the challenge of efficient coupling to incident photons. Common nonlinear optical materials, on the other hand, are easy to couple to but are bulky, imposing a severe limitation on the miniaturization of photonic systems. In this Letter, we show that a single organic molecule acts as an extremely efficient nonlinear optical element in the strong coupling regime of cavity quantum electrodynamics. We report on single-photon sensitivity in nonlinear signal generation and all-optical switching. Our work promotes the use of molecules for applications such as integrated photonic circuits operating at very low powers.

arXiv:2105.02560•Physical Review Letters•Sep 24, 2021•74 citations

Quantum nonlinear optics in one dimension (Conference Presentation)

Nir Rotenberg

At the quantum limit of nonlinear optics, where single photons interact with individual emitters, new phenomena are found. One-dimensional, subwavelength waveguides have recently emerged as a promising quantum optical platform capable of both guiding and confining photons, leading to efficient light-matter interactions and enhancing quantum optical nonlinearities. We explore this regime using both single organic molecules and epitaxially grown quantum dots coupled to nanoscale waveguides. In the first case, two-color experiments allow us to observe distinctly quantum nonlinearities such as Stark shifts of the molecular resonances or amplification without population inversion, although we are limited by relatively weak molecule-waveguide coupling. In contrast, quantum dots can be nearly perfectly coupled to waveguides, allowing us to demonstrate optical nonlinearities at the true single photon level. These, as we discuss, can be used as a basis for novel on-chip quantum technologies.

Ultrafast Phenomena and Nanophotonics•Mar 14, 2018•0 citations

Turning an Organic Molecule into a Coherent Two-Level Quantum System using a Tunable Fabry-Perot Microcavity

Daqing Wang, Hrishikesh Kelkar, Diego Martín-Cano +5 more

By coupling an organic molecule to a Fabry-Perot microcavity, we turn it into a coherent two-level quantum system. We further demonstrate efficient interaction of this system with single photons generated by a second molecule.

Conference on Lasers and Electro-Optics•Jan 1, 2019•0 citations

Turning an Organic Molecule into a Coherent Two-Level Quantum System using a Tunable Fabry-Perot Microcavity

Daqing Wang, Hrishikesh Kelkar, Diego Martín-Cano +5 more

By coupling an organic molecule to a Fabry-Perot microcavity, we turn it into a coherent two-level quantum system. We further demonstrate efficient interaction of this system with single photons generated by a second molecule. © 2019 The Author(s)

Conference on Lasers and Electro-Optics•May 1, 2019•0 citations

Optical Cavity Design and Functionality for Molecular Strong Coupling

Kenji Hirai, James Andell Hutchison, Hiroshi Uji‐i

Optical cavity/molecule strong coupling offers attractive opportunities to modulate photochemical or photophysical processes. When atoms or molecules are placed in an optical cavity, they can coherently exchange photonic energy with optical cavity vacuum fields, entering the strong coupling interaction regime. Recent work suggests that the thermodynamic and kinetic properties of molecules can be significantly changed by strong coupling, resulting in the emergence of intriguing photochemical and photophysical phenomena. As more and more physico-chemical systems are studied under strong coupling conditions, optical cavities have also advanced in their sophistication, responsiveness, and (multi)functionality. In this review, we highlight some of these recent developments, particularly focusing on Fabry-Perot microcavities.

Chemistry - A European Journal•Nov 9, 2023•13 citations

Quantum supercavity with atomic mirrors

Lan Zhou, Hongxing Dong, Yu-xi Liu +2 more

We study single-photon transport in an array of coupled microcavities where two two-level atomic systems are embedded in two separate cavities of the array. We find that a single photon can be totally reflected by a single two-level system. However, two separate two-level systems can also create, between them, single-photon quasibound states. Therefore, a single two-level system in the cavity array can act as a mirror while a different type of cavity can be formed by using two two-level systems, acting as tunable ``mirrors,'' inside two separate cavities in the array. In analogy with superlattices in solid state physics, we call this ``cavity inside a coupled-cavity array'' a supercavity. This supercavity is the quantum analog of Fabry-Perot interferometers. Moreover, we show that the physical properties of this quantum supercavity can be adjusted by changing the frequencies of these two-level systems.

arXiv:0809.4063•Physical Review A•Dec 16, 2008•173 citations
Abstract Control of light–matter coupling at the quantum level is an enabling technique for many emerging quantum technologies. This tutorial describes recent advances in achieving efficient coupling of light with a single molecule using an optical Fabry–Perot microcavity. We demonstrate that the efficient cavity-molecule coupling converts the molecule to an effective two-level system. In this regime, a single molecule can act as a nearly perfect reflecting mirror and exhibits optical nonlinearity at the ultimate level of single photons.
A single quantum emitter can possess a very strong intrinsic nonlinearity, but its overall promise for nonlinear effects is hampered by the challenge of efficient coupling to incident photons. Common nonlinear optical materials, on the other hand, are easy to couple to but are bulky, imposing a severe limitation on the miniaturization of photonic systems. In this Letter, we show that a single organic molecule acts as an extremely efficient nonlinear optical element in the strong coupling regime of cavity quantum electrodynamics. We report on single-photon sensitivity in nonlinear signal generation and all-optical switching. Our work promotes the use of molecules for applications such as integrated photonic circuits operating at very low powers.
At the quantum limit of nonlinear optics, where single photons interact with individual emitters, new phenomena are found. One-dimensional, subwavelength waveguides have recently emerged as a promising quantum optical platform capable of both guiding and confining photons, leading to efficient light-matter interactions and enhancing quantum optical nonlinearities. We explore this regime using both single organic molecules and epitaxially grown quantum dots coupled to nanoscale waveguides. In the first case, two-color experiments allow us to observe distinctly quantum nonlinearities such as Stark shifts of the molecular resonances or amplification without population inversion, although we are limited by relatively weak molecule-waveguide coupling. In contrast, quantum dots can be nearly perfectly coupled to waveguides, allowing us to demonstrate optical nonlinearities at the true single photon level. These, as we discuss, can be used as a basis for novel on-chip quantum technologies.
Optical cavity/molecule strong coupling offers attractive opportunities to modulate photochemical or photophysical processes. When atoms or molecules are placed in an optical cavity, they can coherently exchange photonic energy with optical cavity vacuum fields, entering the strong coupling interaction regime. Recent work suggests that the thermodynamic and kinetic properties of molecules can be significantly changed by strong coupling, resulting in the emergence of intriguing photochemical and photophysical phenomena. As more and more physico-chemical systems are studied under strong coupling conditions, optical cavities have also advanced in their sophistication, responsiveness, and (multi)functionality. In this review, we highlight some of these recent developments, particularly focusing on Fabry-Perot microcavities.
We study single-photon transport in an array of coupled microcavities where two two-level atomic systems are embedded in two separate cavities of the array. We find that a single photon can be totally reflected by a single two-level system. However, two separate two-level systems can also create, between them, single-photon quasibound states. Therefore, a single two-level system in the cavity array can act as a mirror while a different type of cavity can be formed by using two two-level systems, acting as tunable ``mirrors,'' inside two separate cavities in the array. In analogy with superlattices in solid state physics, we call this ``cavity inside a coupled-cavity array'' a supercavity. This supercavity is the quantum analog of Fabry-Perot interferometers. Moreover, we show that the physical properties of this quantum supercavity can be adjusted by changing the frequencies of these two-level systems.