New Discovery - Crucial For The Future Of Quantum Computing

20 February, 2013

Share this story:
Follow us: - In a future of quantum computing, data will be treated and transmitted by lasers. The quantum properties of light will endow machines with gigantic computing potential and an incredible execution rate.

An important discovery - a new way of emitting photons one at a time, with implications for the future of quantum computing is reported by scientists led by Prof. Anna Fontcuberta i Morral, of the Laboratory of Semiconductor Materials (LMSC) of Institute of Materials, Ecole Polytechnique Federale de Lausanne, Switzerland.

Scientists have constructed semiconductor nanowires with "quantum dots" of unprecedented quality.

Prof. Moral found that "quantum dots", or nanocrystals, appear naturally on a certain kind of semiconductor nanowire during their fabrication process.

Nanowires, with a diametre of around a millionth of a millimetre (between 20 and 100 nanometres) are very efficient at absorbing and manipulating light. By endowing them with nanocrystals or "quantum dots" it is possible to make them emit unique photons, by charging them with a laser beam of a particular frequency.

The final structure can then emit photos one by one, after having absorbed light.

However, it's only the beginning and still much work remains to be done. At the present time the phenomenon of the natural creation of dots is not understood by scientists.

In order to exploit the "quantum" potential of light it is necessary, among other things, to be able easily to emit photons one by one.

The only hitch is that generating quantum dots on a nanowire is notoriously difficult.

The existing methods, which involve the use of a regular modulation of the composition of the nanowire all along its length, are hard to reproduce and result in strucures with a relatively low output of photons.

Scientists at the LMSC discovered that perfectly functional quantum dots formed "naturally" on the surface of certain nanowires during the fabrication process.

These dots appeared all by themselves at the interface between two basic components: Gallium Arsenide (GaAs) and Aluminium Arsenide (AlAs).

"No doubt many scientists working on nanowires have created dots, without realising it," states Anna Fontcuberta i Morral.

Credit: 2013 EPFL

"The calculations and simulations were carried out on the supercomputers of EPFL by the Laboratory of the Theory and Simulation of Materials (THEOS) of Nicola Marzari," says Prof. Morral.

As a result, these structures showed a great working stability, which is rare when talking about nanotechnology. What is more they are hard wearing and very bright, which means that their rate of photon output is incredibly high. Even better, by controlling the fabrication of the nanowires, the size of the dots can be modulated and adapted to measure.

Credit: 2013 EPFL

The wavelength of the emitted photons, which is directly dependent on the size of the dots, can therefore be changed. It is then possible for the nanowire to receive a laser beam of a certain wavelength or "colour", in order to generate photons of a certain colour - infrared, for example.

"It is also about seeing if it is possible to stimulate dots not only with lasers but electrically, in order to make them as compatible as we can with all kinds of machine," explains Anna Fontcuberta i Morral.

In a traditional computer, calculations are based on the "bit", which can have one of two values: 0 or 1. This is the essence of binary language. In a quantum computer the "qbit" (for example a photon) can have several states at once, states of superposition. It can be either 0 or 1 or both at the same time.

The aim is maintain photons in their state of superposition so that the computer can carry out multiple calculations in parallel, simultaneously, which will drastically increase the speed of data manipulation. However this capacity for finding several states at once can not be achieved with a photon unless it is isolated: sources of unique photons are therefore much sought after.

Scientific paper on the subject.

See also:
A Milestone Towards Future Satellite-Based Quantum Teleportation Achieved But Race Still Continues!

European Physicists Break Quantum Teleportation Record!

Follow for the latest news on Facebook and Twitter !

Don't Miss Our Stories! Get Our Daily Email Newsletter

Enter your email address:

Once you have confirmed your email address, you will be subscribed to the newsletter.

Recommend this article:

Space-Time Crystal Computer That Can Outlive Even The Universe Itself!

It may seem strange to think something can survive even the death of the Universe, but that could actually be possible as a result of the laws of quantum physics. Scientists are now suggesting a new blueprint for a device, known as a time crystal, that can theoretically continue to function as a computer even after the universe cools to absolute zero.

Is This What Humans Will Look Like In Millions Of Years From Now?

Entering The Worlds Of Moving Holograms

Subscribe To Our Space, Astronomy, Astrophysics, Earth and Xenology News!

Grab the latest RSS feeds right to your reader, desktop or mobile phone.

Subscribe to RSS headline updates from:
Powered by FeedBurner


Copyright @ All rights reserved.

Advertise With Us!


Get our top stories

 Subscribe in a reader

Join Us On Facebook!

Other Popular Articles


Don't Use Your Ipad Or Mobile Phone Shortly Before Bed: Scientists Warn Gadgets With A Backlit Display Can Cause Sleep Problems

NASA's 'Mighty Eagle' Robotic Prototype Lander Takes Successful 100-Foot Free Flight

Nico Demonstrates Robots Can Learn To Be Self-Aware

Amazing Star Wars Hoverbike Successfully Tested And It Looks Just Like In "Return of the Jedi"

Closer To Realistic Virtual Worlds - Disney Researchers Reproduce Human Face!

Car That Can Fold Itself Up: HIRIKO Can Squeeze Into Really Tiny Spaces!

Soon We'll Enjoy 3D Films Without Special Glasses And In Real-Time!

Hacking Your Brain And Extracting Sensitive Information Will Soon Be Possible

Silicone-Based Robots Can Walk And Change Their Appearance

Biometrics: Eye-Scanners Can Be Fooled

Iris scanning technologies allow people to use their eyes to prove their identify. S canning your iris has been considered a very good security tool, but now it turns out it is actually possible to fool eye-scanners!

Upload Your Brain Into A Hologram: Project Avatar 2045 - A New Era For Humanity Or Scientific Madness?

Would you like to live forever? What do you think about the idea that your conscious mind will be uploaded into a hologram? How far should scientists go in their quest for human immortality? Theses are just some of the many questions that concern Project Avatar 2045.

Our Universe Is A Gigantic And Wonderfully Detailed Holographic Illusion

Peoples' Thoughts Should Be Recorded And Made Public Scientist Suggests - Total Mind Control Or Ultimate Freedom?

Our Brain Is A Holographic Machine Existing In A Holographic Universe

The Strange World Of Space-Time - Not As Many Bubbles As Previously Thought

Shockwaves Could Crinkle Space-Time Creating A New Kind Of Singularity