Nanooptical traps are a promising building block for quantum technologies. Austrian and German scientists have now removed an important obstacle to their practical use. They were able to show that a special form of mechanical vibration heats trapped particles in a very short time and knocks them out of the trap.
By controlling individual atoms, quantum properties can be investigated and made usable for technological applications. For about ten years, physicists have been working on a technology that can capture and control atoms: so-called nanooptical traps.
The technique of capturing microscopic objects with light known from optical tweezers is applied to optical waveguides, in this case a special glass fiber. The glass fiber may only be a few hundred nanometers thin, i.e. about 100 times thinner than a human hair. Laser light of different frequencies is sent into the glass fiber, creating a light field around the waveguide that can hold individual atoms.
Up to now, however, the applicability of this technology has been limited by the fact that the atoms have become very hot after a very short time and are lost. The heating rate was three orders of magnitude higher than with optical tweezers, where the light field is generated in free space. Despite an intensive search, it had previously not been possible to determine the cause.
Now Daniel Hümmer and Oriol Romero-Isart from the Institute of Quantum Optics and Quantum Information of the Austrian Academy of Sciences and the Department of Theoretical Physics at the University of Innsbruck in cooperation with Philipp Schneeweiss and Arno Rauschenbeutel from the Humboldt University of Berlin have carefully analyzed the system.
With their theoretical model, they were able to show that a certain form of mechanical vibration of the glass fiber is responsible for the strong heating of the particles. This is reported by the physicists in the journal Physical Review X.
"These are the vibrations that arise when you let waves travel along a rope," explains Daniel Hümmer. "The particles, which float only about 200 nanometers above the surface of the waveguide, heat up very quickly because of these vibrations." The heating rate that has now been theoretically determined agrees very well with the experimental results.
This finding has important consequences for applications: On the one hand, the technology can be significantly improved with simple counter-measures. Longer coherence times then allow more complex experiments and applications. On the other hand, the physicists suspect that their findings could also be helpful for many similar nanophotonic traps.
The theoretical model they have now published provides essential guidelines for the design of such atomic traps. "When manufacturing these traps, not only the optical properties must be taken into account, but also the mechanical properties," stresses Oriol Romero-Isart. "Our calculations here give important indications as to which mechanical effects are most relevant.”
Since the strength of the interaction between individual atoms and photons is particularly high in nanooptical traps - a problem with which many other concepts struggle - this technology opens the door to a new field of physics. Many theoretical considerations have already been made in recent years. The physicists from Austria and Germany have now cleared away a major obstacle on the way there.
The research was financially supported by the European Research Council (ERC), the Austrian Academy of Sciences and the Austrian Federal Ministry of Education, Science and Research.
Institute of Quantum Optics and Quantum Information
Austrian Academy of Sciences
phone: +43 512 507 52257
Heating in Nanophotonic Traps for Cold Atoms. Daniel Hümmer, Philipp Schneeweiss, Arno Rauschenbeutel, and Oriol Romero-Isart. Phys. Rev. X 9, 041034
DOI: 10.1103/PhysRevX.9.041034 https://doi.org/10.1103/PhysRevX.9.041034
Dr. Christian Flatz | Universität Innsbruck
Swiss space telescope CHEOPS: Rocket launch set for 17 December 2019
05.12.2019 | Universität Bern
A question of pressure
05.12.2019 | Physikalisch-Technische Bundesanstalt (PTB)
With ultracold chemistry, researchers get a first look at exactly what happens during a chemical reaction
The coldest chemical reaction in the known universe took place in what appears to be a chaotic mess of lasers. The appearance deceives: Deep within that...
Abnormal scarring is a serious threat resulting in non-healing chronic wounds or fibrosis. Scars form when fibroblasts, a type of cell of connective tissue, reach wounded skin and deposit plugs of extracellular matrix. Until today, the question about the exact anatomical origin of these fibroblasts has not been answered. In order to find potential ways of influencing the scarring process, the team of Dr. Yuval Rinkevich, Group Leader for Regenerative Biology at the Institute of Lung Biology and Disease at Helmholtz Zentrum München, aimed to finally find an answer. As it was already known that all scars derive from a fibroblast lineage expressing the Engrailed-1 gene - a lineage not only present in skin, but also in fascia - the researchers intentionally tried to understand whether or not fascia might be the origin of fibroblasts.
Fibroblasts kit - ready to heal wounds
Research from a leading international expert on the health of the Great Lakes suggests that the growing intensity and scale of pollution from plastics poses serious risks to human health and will continue to have profound consequences on the ecosystem.
In an article published this month in the Journal of Waste Resources and Recycling, Gail Krantzberg, a professor in the Booth School of Engineering Practice...
Conventional light microscopes cannot distinguish structures when they are separated by a distance smaller than, roughly, the wavelength of light. Superresolution microscopy, developed since the 1980s, lifts this limitation, using fluorescent moieties. Scientists at the Max Planck Institute for Polymer Research have now discovered that graphene nano-molecules can be used to improve this microscopy technique. These graphene nano-molecules offer a number of substantial advantages over the materials previously used, making superresolution microscopy even more versatile.
Microscopy is an important investigation method, in physics, biology, medicine, and many other sciences. However, it has one disadvantage: its resolution is...
03.12.2019 | Event News
15.11.2019 | Event News
15.11.2019 | Event News
05.12.2019 | Physics and Astronomy
05.12.2019 | Life Sciences
05.12.2019 | Life Sciences