In the current issue of Nature Photonics, a research team of Innsbruck physicists led by Rainer Blatt and Tracy Northup report how they have directly transferred the quantum information stored in an atom onto a particle of light. Such information could then be sent over optical fiber to a distant atom.
Thanks to the strange laws of quantum mechanics, quantum computers would be able to carry out certain computational tasks much faster than conventional computers. Among the most promising technologies for the construction of a quantum computer are systems of single atoms, confined in so-called ion traps and manipulated with lasers. In the laboratory, these systems have already been used to test key building blocks of a future quantum computer. “Currently, we can carry out successful quantum computations with atoms,” explain Andreas Stute and Bernardo Casabone, both PhD students at the University of Innsbruck’s Institute for Experimental Physics. “But we are still missing viable interfaces with which quantum information can be transferred over optical channels from one computer to another.”
What makes the construction of these interfaces especially challenging is that the laws of quantum mechanics don’t allow quantum information to be simply copied. Instead, a future quantum internet – that is, a network of quantum computers linked by optical channels – would have to transfer quantum information onto individual particles of light, known as photons. These photons would then be transported over an optical-fiber link to a distant computing site. Now, for the first time, quantum information has been directly transferred from an atom in an ion trap onto a single photon. The work is reported in the current issue of Nature Photonics by a research team led by Tracy Northup and Rainer Blatt.
The University of Innsbruck physicists first trap a single calcium ion in an ion trap and position it between two highly reflective mirrors. “We use a laser to write the desired quantum information onto the electronic states of the atom,” explains Stute. “The atom is then excited with a second laser, and as a result, it emits a photon. At this moment, we write the atom’s quantum information onto the polarization state of the photon, thus mapping it onto the light particle.” The photon is stored between the mirrors until it eventually flies out through one mirror, which is less reflective than the other. “The two mirrors steer the photon in a specific direction, effectively guiding it into an optical fiber,” says Casabone. The quantum information stored in the photon could thus be conveyed over the optical fiber to a distant quantum computer, where the same technique could be applied in reverse to write it back onto an atom.
Support for this research was provided by the Austrian Science Funds and by the European Union.
Publication: Quantum-state transfer from an ion to a photon. A. Stute, B. Casabone, B. Brandstätter, K. Friebe, T. E. Northup, R. Blatt. Nature Photonics 2013 DOI: 10.1038/NPHOTON.2012.358 (http://dx.doi.org/10.1038/NPHOTON.2012.358)
Institute for Experimental Physics
University of Innsbruck, Austria
Tel.: +43 512 507-52465
Public Relations Office
University of Innsbruck
Tel.: +43 512 507-32022
Mobil: +43 676 872532022
Dr. Christian Flatz | Source: Universität Innsbruck
Further information: www.uibk.ac.at
More articles from Physics and Astronomy:
A Hidden Population of Exotic Neutron Stars
24.05.2013 | Chandra X-ray Center
Hubble reveals the Ring Nebula’s true shape
24.05.2013 | NASA/Goddard Space Flight Center
This morning at 05:45 CEST, the earth trembled beneath the Okhotsk Sea in the Pacific Northwest. The quake, with a magnitude of 8.2, took place at an exceptional depth of 605 kilometers.
Because of the great depth of the earthquake a tsunami is not expected and there should also be no major damage due to shaking.
Professor Frederik Tilmann of the GFZ German Research Centre for Geosciences: "The epicenter is exceptionally deep, far below the earth's crust in the mantle. Such strong ...
The Ring Nebula's distinctive shape makes it a popular illustration for astronomy books. But new observations by NASA's Hubble Space Telescope of the glowing gas shroud around an old, dying, sun-like star reveal a new twist.
"The nebula is not like a bagel, but rather, it's like a jelly doughnut, because it's filled with material in the middle," said C. Robert O'Dell of Vanderbilt University in Nashville, Tenn.
He leads a research team that used Hubble and several ground-based telescopes to obtain the best view yet of ...
New indicator molecules visualise the activation of auto-aggressive T cells in the body as never before
Biological processes are generally based on events at the molecular and cellular level. To understand what happens in the course of infections, diseases or normal bodily functions, scientists would need to examine individual cells and their activity directly in the tissue.
The development of new microscopes and fluorescent dyes in ...
A fried breakfast food popular in Spain provided the inspiration for the development of doughnut-shaped droplets that may provide scientists with a new approach for studying fundamental issues in physics, mathematics and materials.
The doughnut-shaped droplets, a shape known as toroidal, are formed from two dissimilar liquids using a simple rotating stage and an injection needle. About a millimeter in overall size, the droplets are produced individually, their shapes maintained by a surrounding springy material made of polymers.
Droplets in this toroidal shape made ...
Frauhofer FEP will present a novel roll-to-roll manufacturing process for high-barriers and functional films for flexible displays at the SID DisplayWeek 2013 in Vancouver – the International showcase for the Display Industry.
Displays that are flexible and paper thin at the same time?! What might still seem like science fiction will be a major topic at the SID Display Week 2013 that currently takes place in Vancouver in Canada.
High manufacturing cost and a short lifetime are still a major obstacle on ...
24.05.2013 | Life Sciences
24.05.2013 | Ecology, The Environment and Conservation
24.05.2013 | Physics and Astronomy
17.05.2013 | Event News
15.05.2013 | Event News
08.05.2013 | Event News