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

Optical and Quantum Sensing and Precision Metrology II

Realization of ensemble atom trapping and collective atom-photon coupling on a nanophotonic microring circuit

Xinchao Zhou, Hikaru Tamura, Tzu-Han Chang, Chen-Lung Hung

Published Mar 13, 2024• 0 citations
Publisher

Abstract

We discuss our recent experiment demonstrating superradiantly-coupled trapped atomic ensemble in an optical microtrap above a nanophotonic microring resonator. Here, efficient trap loading is achieved via a degenerate Raman-sideband cooling (dRSC) scheme using built-in spin-motion coupling in the microtrap and a single optical pumping beam sent from freespace. We show that these dRSC-cooled atoms display large cooperative coupling and enhanced superradiant decay into a whispering-gallery mode in the microring resonator.

DOI
10.1117/12.3012158

Related papers

Trapped Atoms and Superradiance on an Integrated Nanophotonic Microring Circuit

Xinchao Zhou, Hikaru Tamura, Tzu-Han Chang +1 more

Interfacing cold atoms with integrated nanophotonic devices could offer new paradigms for engineering atom-light interactions and provide a potentially scalable route for quantum sensing, metrology, and quantum information processing. However, it remains a challenging task to efficiently trap a large ensemble of cold atoms on an integrated nanophotonic circuit. Here, we demonstrate direct loading of an ensemble of up to 70 atoms into an optical microtrap on a nanophotonic microring circuit. Efficient trap loading is achieved by employing degenerate Raman-sideband cooling in the microtrap, where a built-in spin-motion coupling arises directly from the vector light shift of the evanescent-field potential on a microring. Atoms are cooled into the trap via optical pumping with a single free space beam. We have achieved a trap lifetime approaching 700 ms under continuous cooling. We show that the trapped atoms display large cooperative coupling and superradiant decay into a whispering-gallery mode of the microring resonator, holding promise for explorations of new collective effects. Our technique can be extended to trapping a large ensemble of cold atoms on nanophotonic circuits for various quantum applications. Published by the American Physical Society 2024

arXiv:2312.14318•Physical Review X•Jul 9, 2024•33 citations

Coupling Single Atoms to a Nanophotonic Whispering-Gallery-Mode Resonator via Optical Guiding

Xinchao Zhou, Hikaru Tamura, Tzu-Han Chang +1 more

We demonstrate an efficient optical guiding technique for coupling cold atoms in the near field of a planar nanophotonic circuit, and realize large atom-photon coupling to a whispering-gallery mode in a microring resonator with a single-atom cooperativity C≳8. The guiding potential is created by diffracted light on a nanophotonic waveguide that smoothly connects to a dipole trap in the far field for atom guiding with subwavelength precision. We observe atom-induced transparency for light coupled to a microring, characterize the atom-photon coupling rate, extract guided atom flux, and demonstrate on-chip photon routing by single atoms. Our demonstration promises new applications with cold atoms on a nanophotonic circuit for chiral quantum optics and quantum technologies.

arXiv:2111.01119•Physical Review Letters•Mar 7, 2023•40 citations

Coupling single atoms and molecules to nanophotonic resonators

Ming Yuan Zhu, Tzu-Han Chang, Yan-Cheng Wei +4 more

The integration of cold neutral atoms with nanophotonic circuits offers significant potential as a light–matter interface for a wide range of applications ranging from fundamental studies in quantum optics, quantum many– body physics, quantum networks to even ultracold chemistry. Here, we describe the design and realization of a novel platform where an efficiently–coupled microring photonic circuit on a chip is integrated with a cold atom system. This platform is fully compatible with laser cooling and trapping atoms, which allows for direct loading of cold atoms in close vicinity of a microring circuit. We discuss our experimental scheme and efforts to prepare for an array of individually trapped atoms within the near field region of a whispering-gallery mode (WGM) in a microring resonator for realizing strong atom–light interactions. Beyond our original motivations in creating an atom-photon quantum interface, we also discuss a novel application – for direct photoassociation (PA) synthesis and quantum state detection of cold diatomic molecules without closed optical transitions. We estimate that the transfer efficiency to a molecular ground state and the subsequent state detection efficiency can approach unity with strong photon–molecule coupling that could be realized in our microring resonator circuit.

Optical and Quantum Sensing and Precision Metrology•Mar 4, 2021•0 citations

Collective emission dynamics of many atoms coupled to a nanophotonic resonator

Ahreum Lee, Xinchao Zhou, Dipanjan Das +3 more

Neutral atoms collectively coupled to a nanophotonic chip are key building blocks for quantum computers and quantum networks. We present our platform of cesium atoms integrated with a microring resonator, where approximately 70 atoms are trapped about 350 nm above from the microring surface using optical guiding and degenerate Raman sideband cooling. This setup enables the exploration of collective dynamics mediated by guided and radiative modes, leading to the observation of selective collective emission into the microring. We further discuss our progress toward implementing an evanescent trap geometry, which allows atoms to be brought closer to the microring surface and introduces spatial ordering. Trapping and cooling atoms in close proximity to nanophotonic structures advance the study of collective quantum optics and pave the way toward scalable quantum computers.

Optical and Quantum Sensing and Precision Metrology II•Mar 5, 2026•0 citations

Selective Collective Emission from a Dense Atomic Ensemble Coupled to a Nanophotonic Resonator

Xinchao Zhou, Deepak A. Suresh, F. Robicheaux +1 more

We experimentally and theoretically study collective emission of a dense atomic ensemble coupled to a single mode in a nanophotonic microring resonator. Because many cold atoms are localized in a small volume, these trapped atoms collectively couple not only to the guided resonator mode but also to the nonguided modes in free space. Through tuning the atom-photon coupling and by adjusting the number of trapped atoms, we demonstrate superradiant emission to the microring resonator. For photon emission via the nonguided modes, our study reveals signatures of subradiance and superradiance when the system is driven to the steady state and to the timed-Dicke state, respectively. Our experimental platform thus presents the first atom-light interface with selective collective emission behavior into a guided mode and the environment. Our observation and methodology could shed light on future explorations of collective emission with densely packed quantum emitters coupled to nanophotonic light-matter interfaces.

arXiv:2503.05664•Physical Review Letters•Aug 14, 2025•4 citations

Microring resonators on a suspended membrane circuit for atom-light interactions

Hikaru Tamura, Tzu-Han Chang, Xinchao Zhou +3 more

The integration of cold neutral atoms with nanophotonic circuits offers significant potential as a light–mater interface for a wide range of applications ranging from studies of fundamental physics and quantum many– body physics to quantum networks. Here, we describe the design and realization of a novel platform where an efficiently–coupled microring photonic circuit on a chip is integrated with a cold atom system. This platform is fully compatible with laser cooling and trapping atoms, which allows for direct loading of cold atoms into an optical tweezer lattice formed on the microring circuit. Realizing strong atom–light interaction requires localizing atoms within the near field region of a whispering-gallery mode in a microring resonator. To this end, we estimate the positions of trapped atoms and consider a scheme to transport them to the closest site from the surface. This scheme can also be used for preparing for an array of individually trapped atoms. Such a platform holds promises for realizing a robust and scalable light–mater interface operating at individual quanta.

Integrated Optics: Devices, Materials, and Technologies•Mar 4, 2021•0 citations
We discuss our recent experiment demonstrating superradiantly-coupled trapped atomic ensemble in an optical microtrap above a nanophotonic microring resonator. Here, efficient trap loading is achieved via a degenerate Raman-sideband cooling (dRSC) scheme using built-in spin-motion coupling in the microtrap and a single optical pumping beam sent from freespace. We show that these dRSC-cooled atoms display large cooperative coupling and enhanced superradiant decay into a whispering-gallery mode in the microring resonator.
Interfacing cold atoms with integrated nanophotonic devices could offer new paradigms for engineering atom-light interactions and provide a potentially scalable route for quantum sensing, metrology, and quantum information processing. However, it remains a challenging task to efficiently trap a large ensemble of cold atoms on an integrated nanophotonic circuit. Here, we demonstrate direct loading of an ensemble of up to 70 atoms into an optical microtrap on a nanophotonic microring circuit. Efficient trap loading is achieved by employing degenerate Raman-sideband cooling in the microtrap, where a built-in spin-motion coupling arises directly from the vector light shift of the evanescent-field potential on a microring. Atoms are cooled into the trap via optical pumping with a single free space beam. We have achieved a trap lifetime approaching 700 ms under continuous cooling. We show that the trapped atoms display large cooperative coupling and superradiant decay into a whispering-gallery mode of the microring resonator, holding promise for explorations of new collective effects. Our technique can be extended to trapping a large ensemble of cold atoms on nanophotonic circuits for various quantum applications. Published by the American Physical Society 2024
We demonstrate an efficient optical guiding technique for coupling cold atoms in the near field of a planar nanophotonic circuit, and realize large atom-photon coupling to a whispering-gallery mode in a microring resonator with a single-atom cooperativity C≳8. The guiding potential is created by diffracted light on a nanophotonic waveguide that smoothly connects to a dipole trap in the far field for atom guiding with subwavelength precision. We observe atom-induced transparency for light coupled to a microring, characterize the atom-photon coupling rate, extract guided atom flux, and demonstrate on-chip photon routing by single atoms. Our demonstration promises new applications with cold atoms on a nanophotonic circuit for chiral quantum optics and quantum technologies.
The integration of cold neutral atoms with nanophotonic circuits offers significant potential as a light–matter interface for a wide range of applications ranging from fundamental studies in quantum optics, quantum many– body physics, quantum networks to even ultracold chemistry. Here, we describe the design and realization of a novel platform where an efficiently–coupled microring photonic circuit on a chip is integrated with a cold atom system. This platform is fully compatible with laser cooling and trapping atoms, which allows for direct loading of cold atoms in close vicinity of a microring circuit. We discuss our experimental scheme and efforts to prepare for an array of individually trapped atoms within the near field region of a whispering-gallery mode (WGM) in a microring resonator for realizing strong atom–light interactions. Beyond our original motivations in creating an atom-photon quantum interface, we also discuss a novel application – for direct photoassociation (PA) synthesis and quantum state detection of cold diatomic molecules without closed optical transitions. We estimate that the transfer efficiency to a molecular ground state and the subsequent state detection efficiency can approach unity with strong photon–molecule coupling that could be realized in our microring resonator circuit.
Neutral atoms collectively coupled to a nanophotonic chip are key building blocks for quantum computers and quantum networks. We present our platform of cesium atoms integrated with a microring resonator, where approximately 70 atoms are trapped about 350 nm above from the microring surface using optical guiding and degenerate Raman sideband cooling. This setup enables the exploration of collective dynamics mediated by guided and radiative modes, leading to the observation of selective collective emission into the microring. We further discuss our progress toward implementing an evanescent trap geometry, which allows atoms to be brought closer to the microring surface and introduces spatial ordering. Trapping and cooling atoms in close proximity to nanophotonic structures advance the study of collective quantum optics and pave the way toward scalable quantum computers.
We experimentally and theoretically study collective emission of a dense atomic ensemble coupled to a single mode in a nanophotonic microring resonator. Because many cold atoms are localized in a small volume, these trapped atoms collectively couple not only to the guided resonator mode but also to the nonguided modes in free space. Through tuning the atom-photon coupling and by adjusting the number of trapped atoms, we demonstrate superradiant emission to the microring resonator. For photon emission via the nonguided modes, our study reveals signatures of subradiance and superradiance when the system is driven to the steady state and to the timed-Dicke state, respectively. Our experimental platform thus presents the first atom-light interface with selective collective emission behavior into a guided mode and the environment. Our observation and methodology could shed light on future explorations of collective emission with densely packed quantum emitters coupled to nanophotonic light-matter interfaces.
The integration of cold neutral atoms with nanophotonic circuits offers significant potential as a light–mater interface for a wide range of applications ranging from studies of fundamental physics and quantum many– body physics to quantum networks. Here, we describe the design and realization of a novel platform where an efficiently–coupled microring photonic circuit on a chip is integrated with a cold atom system. This platform is fully compatible with laser cooling and trapping atoms, which allows for direct loading of cold atoms into an optical tweezer lattice formed on the microring circuit. Realizing strong atom–light interaction requires localizing atoms within the near field region of a whispering-gallery mode in a microring resonator. To this end, we estimate the positions of trapped atoms and consider a scheme to transport them to the closest site from the surface. This scheme can also be used for preparing for an array of individually trapped atoms. Such a platform holds promises for realizing a robust and scalable light–mater interface operating at individual quanta.