All News

Laser light traps giant atoms

Published on March 25th, 2020

For the first time, physicists of Kastler Brossel Laboratory have been able to use light to trap giant atoms, so-called circular Rydberg atoms. This work will push the limits of currently developed quantum technologies that use these atoms of remarkable properties.


Rydberg atoms have proved particularly useful in the development of current quantum technologies. These giant atoms, almost as large as bacteria, show remarkable properties. Their strong mutual interactions and their strong coupling to electromagnetic fields make them well suited to the realization of highly-sensitive field probes, quantum simulators or even quantum computers. Moreover, atoms excited to Rydberg levels live very long, few hundreds of microseconds versus few tens of nanoseconds only for weakly excited atoms. In this respect, circular Rydberg atoms, for which the valence electron follows a circular orbit around the nucleus, are exceptional. Their lifetimes reach several tens of milliseconds.

However, these experiments have been up to now limited by the fact that Rydberg atoms are not trapped. The experiment’s timescale is then limited to a few microseconds only by the motion of the atoms, atoms that for instance repel each other when they interact. The Cavity Quantum Electrodynamics team of LKB has been able for the first time to keep circular Rydberg atoms inside a light beam, in a work published in Physical Review Letters. Atoms are excited inside a light ring, or Laguerre-Gauss beam, from which they cannot escape. The LKB team has been able to trap the atoms over ten milliseconds and to observe the oscillations of the atoms in the light ring.

This work will allow scientists to push the limit of current Rydberg-based experiments, paving the way to greatly enhanced sensitivity of field probes or to quantum simulations of slow phenomena, such as quantum thermalization.

The study has been conducted with funding from the Quantum Flagship’s PASQuans project.

Link to the Article
Link to the PASQuanS website

Caption: Circular Rydberg atoms are trapped in a hollow laser light tube (artistic view). Image credit: Clément SAYRIN/Laboratoire Kastler Brossel, ENS, SU, CNRS.

More News?

All News
  • Plug and play continuous variable quantum key distribution for metropolitan networks

    The study entitled "Plug and play continuous variable quantum key distribution for metropolitan networks", published by partners of the CiViQ in Optics Express, has been highlighted as an Editor's Pick. Editor's Picks serve to highlight articles with excellent scientific quality and are representative of the work taking place in a specific field.

  • Qombs makes major advances in high performance quantum cascade laser frequency combs

    QOMBS project partner Alpes Lasers has demonstrated high-performance quantum cascade laser frequency combs at λ ∼ 6 μm for the first time. This new wavelength is important because it corresponds to the amide I vibration band of proteins, opening up numerous new biological and medical applications.

  • New software brings quantum network design to users around the world

    NetSquid, a specialized simulator for quantum networks has been made freely available for non-commercial users. In development by QuTech since 2017, the software is the first of its kind to model timing effects using discrete events. NetSquid allows researchers around the world to accurately predict the performance of quantum networks and modular quantum computing systems. Such simulations are essential to design scalable quantum systems and exploit them for radically new types of computation and communication technologies.

All News