Featured Research

from universities, journals, and other organizations

A single-atom light switch: New switch is powerful tool for quantum information and quantum communication

Date:
November 5, 2013
Source:
Vienna University of Technology, TU Vienna
Summary:
With just a single atom, light can be switched between two fiber optic cables. Such a switch enables quantum phenomena to be used for information and communication technology.

The Quantum Light Switch: It can occupy both possible states at the same time.
Credit: Image courtesy of Vienna University of Technology, TU Vienna

With just a single atom, light can be switched between two fibre optic cables at the Vienna University of Technology. Such a switch enables quantum phenomena to be used for information and communication technology.

Fibre optic cables are turned in to a quantum lab: scientists are trying to build optical switches at the smallest possible scale in order to manipulate light. At the Vienna University of Technology, this can now be done using a single atom. Conventional glass fibre cables, which are used for internet data transfer, can be interconnected by tiny quantum systems.

Light in a Bottle

Professor Arno Rauschenbeutel and his team at the Vienna University of Technology capture light in so-called "bottle resonators." At the surface of these bulgy glass objects, light runs in circles. If such a resonator is brought into the vicinity of a glass fibre which is carrying light, the two systems couple and light can cross over from the glass fibre into the bottle resonator.

"When the circumference of the resonator matches the wavelength of the light, we can make one hundred percent of the light from the glass fibre go into the bottle resonator -- and from there it can move on into a second glass fibre," explains Arno Rauschenbeutel.

A Rubidium Atom as a Light Switch

This system, consisting of the incoming fibre, the resonator and the outgoing fibre, is extremely sensitive: "When we take a single Rubidium atom and bring it into contact with the resonator, the behaviour of the system can change dramatically," says Rauschenbeutel. If the light is in resonance with the atom, it is even possible to keep all the light in the original glass fibre, and none of it transfers to the bottle resonator and the outgoing glass fibre. The atom thus acts as a switch which redirects light one or the other fibre.

Both Settings at Once: The Quantum Switch

In the next step, the scientists plan to make use of the fact that the Rubidium atom can occupy different quantum states, only one of which interacts with the resonator. If the atom occupies the non-interacting quantum state, the light behaves as if the atom was not there. Thus, depending on the quantum state of the atom, light is sent into either of the two glass fibres. This opens up the possibility to exploit some of the most remarkable properties of quantum mechanics: "In quantum physics, objects can occupy different states at the same time," says Arno Rauschenbeutel. The atom can be prepared in such a way that it occupies both switch states at once. As a consequence, the states "light" and "no light" are simultaneously present in each of the two glass fibre cables.

For the classical light switch at home, this would be plain impossible, but for a "quantum light switch," occupying both states at once is not a problem. "It will be exciting to test, whether such superpositions are also possible with stronger light pulses. Somewhere we are bound to encounter a crossover between quantum physics and classical physics," says Rauschenbeutel.

This light switch is a very powerful new tool for quantum information and quantum communication. "We are planning to deterministically create quantum entanglement between light and matter," says Arno Rauschenbeutel. "For that, we will no longer need any exotic machinery which is only found in laboratories. Instead, we can now do it with conventional glass fibre cables which are available everywhere."


Story Source:

The above story is based on materials provided by Vienna University of Technology, TU Vienna. Note: Materials may be edited for content and length.


Journal Reference:

  1. Darrick Chang. A Single-Atom Optical Switch. Physics, 2013; 6 DOI: 10.1103/Physics.6.121

Cite This Page:

Vienna University of Technology, TU Vienna. "A single-atom light switch: New switch is powerful tool for quantum information and quantum communication." ScienceDaily. ScienceDaily, 5 November 2013. <www.sciencedaily.com/releases/2013/11/131105103534.htm>.
Vienna University of Technology, TU Vienna. (2013, November 5). A single-atom light switch: New switch is powerful tool for quantum information and quantum communication. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2013/11/131105103534.htm
Vienna University of Technology, TU Vienna. "A single-atom light switch: New switch is powerful tool for quantum information and quantum communication." ScienceDaily. www.sciencedaily.com/releases/2013/11/131105103534.htm (accessed April 23, 2014).

Share This



More Matter & Energy News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Is North Korea Planning Nuclear Test #4?

Is North Korea Planning Nuclear Test #4?

Newsy (Apr. 22, 2014) South Korean officials say North Korea is preparing to conduct another nuclear test, but is Pyongyang just bluffing this time? Video provided by Newsy
Powered by NewsLook.com
China Falls for 4x4s at Beijing Auto Show

China Falls for 4x4s at Beijing Auto Show

AFP (Apr. 22, 2014) The urban 4x4 is the latest must-have for Chinese drivers, whose conversion to the cult of the SUV is the talking point of this year's Beijing auto show. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com
Lytro Introduces 'Illum,' A Professional Light-Field Camera

Lytro Introduces 'Illum,' A Professional Light-Field Camera

Newsy (Apr. 22, 2014) The light-field photography engineers at Lytro unveiled their next innovation: a professional DSLR-like camera called "Illum." Video provided by Newsy
Powered by NewsLook.com
3 Reasons Why Harley Davidson Is Selling Tons of Epic Hogs

3 Reasons Why Harley Davidson Is Selling Tons of Epic Hogs

TheStreet (Apr. 22, 2014) Sales of motorcycles have continued to ride back from the depths of hell known as the Great Recession. Excluding scooters, sales of motorcycles increased 3% in 2013. In units, however, at 465,000 sold last year, the total remained about 50% below the peak hit in 2007. Industry leader Harley Davidson’s shareholders have benefited both by the industry recovery and positive headlines emanating from the company. Belus Capital Advisors CEO Brian Sozzi takes you beyond the headlines of the motorcycle maker. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins