Featured Research

from universities, journals, and other organizations

How Photon Echoes Can Be Used To Create A Quantum Memory Device

Date:
September 14, 2009
Source:
Australian National University
Summary:
A new way of storing and 'echoing' pulses of light has been discovered by a team from Australia, allowing bursts of laser to work as a flexible optical memory and potentially assist in extending the range of quantum information systems.

The experiment that generated the photon echo effect.
Credit: Image courtesy of Australian National University

A new way of storing and ‘echoing’ pulses of light has been discovered by a team from The Australian National University, allowing bursts of laser to work as a flexible optical memory and potentially assist in extending the range of quantum information systems.

Technologies like quantum cryptography are being developed to send secure information coded onto light beams from one point to another. Yet at present these systems are unable to extend beyond a distance of 50 to 100 kilometres because, beyond that range, too much of the information is lost.

But a team based at the ARC Centre of Excellence in Quantum-Atom Optics at ANU has demonstrated how photon echoes can be used to create a quantum memory device – meaning that pulses of light can be captured, stored and then released on demand. Such a device would be an important part of a quantum repeater, which could extend the range of secure quantum communication.

“Light can be a fantastic medium for transferring lots of information very quickly, but it doesn’t like to stay in one place for long,” explains team member Dr Ben Buchler. “This is the problem of optical memory – how to keep the information coded on light in one place so you can access it again later. One method is to slow the light down so it’s as good as frozen in place for a while. The way we’ve explored is to absorb the light in a cloud of atoms, which you can then manipulate to release the light at will.”

In experiments performed by PhD candidate Mahdi Hosseini, the ANU research team developed a method where pulses of laser light are absorbed into a cloud of atoms surrounded by a coil of wire. The coil creates a magnetic field that shifts the frequency of the atoms. After absorbing the laser pulses, the atoms all begin to spin at different speeds, depending on their frequency. If the magnetic field is reversed, the atoms all change direction and spin the other way. When the spinning atoms return to the state they were in when they absorbed the light, the laser pulses are released as a photon echo.

“But we take it a few steps further,” explains Dr Buchler. “We can also stretch, compress and split the pulses when we let them out. Best of all, we can recall the pulses in any order, just like a random access memory in a computer can recall electronic information in any order. To do this we use a second control laser beam that can turn the photon echo on and off. In a regular photon echo system, once the atoms all re-align the stored light just comes out – you can’t stop it. In our system, the combination of control beam and magnetic field switching makes it possible to choose exactly when to recall any one of the stored pulses, how much of it to recall and how fast to recall it.”

The research, published in Nature, outlines how the team have managed to store laser pulses with efficiencies above 40 per cent using its technique. The team includes Dr Ben Buchler, Ben Sparkes, Gabriel Hetet, Mahdi Hosseini, Dr Jevon Longdell (now at the University of Otago) and Professor Ping Koy Lam from ANU.


Story Source:

The above story is based on materials provided by Australian National University. Note: Materials may be edited for content and length.


Cite This Page:

Australian National University. "How Photon Echoes Can Be Used To Create A Quantum Memory Device." ScienceDaily. ScienceDaily, 14 September 2009. <www.sciencedaily.com/releases/2009/09/090911132308.htm>.
Australian National University. (2009, September 14). How Photon Echoes Can Be Used To Create A Quantum Memory Device. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2009/09/090911132308.htm
Australian National University. "How Photon Echoes Can Be Used To Create A Quantum Memory Device." ScienceDaily. www.sciencedaily.com/releases/2009/09/090911132308.htm (accessed October 1, 2014).

Share This



More Matter & Energy News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Argentina's Tax Evaders Detected, Hunted Down by Drones

Argentina's Tax Evaders Detected, Hunted Down by Drones

AFP (Sep. 30, 2014) Argentina doesn't only have Lionel Messi the footballer, it has now also acquired "Mesi" the drone system which monitors undeclared mansions, swimming pools and soy fields to curb tax evasion in the country. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Do Video Games Trump Brain Training For Cognitive Boosts?

Do Video Games Trump Brain Training For Cognitive Boosts?

Newsy (Sep. 29, 2014) More and more studies are showing positive benefits to playing video games, but the jury is still out on brain training programs. Video provided by Newsy
Powered by NewsLook.com
CERN Celebrates 60 Years of Science

CERN Celebrates 60 Years of Science

Reuters - Business Video Online (Sep. 29, 2014) CERN, the European Organisation for Nuclear Research, celebrates 60 years of bringing nations together through science. As Joanna Partridge reports from inside the famous science centre it's also planning to turn the Large Hadron Collider particle accelerator back on after an upgrade. Video provided by Reuters
Powered by NewsLook.com
This 'Invisibility Cloak' Is Simpler Than Most

This 'Invisibility Cloak' Is Simpler Than Most

Newsy (Sep. 28, 2014) Researchers from the University of Rochester have created a type of invisibility cloak with simple focal lenses. Video provided by Newsy
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:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

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