Single Atom Quantum Memory

The storage and regeneration of quantum qubits is is essential for the development of quantum computing and communications systems. Today, Holger Specht and colleagues at the Max Planck Institute for Quantum Optics in Garching, Germany, have found a way to store the qubit from a polarized photon in a single atom of rubidium and then release it again later.


(Single Atom Quantum Memory)
a, A single atom (1) (the inset shows a typical fluorescence image) is trapped at the centre of a high-finesse optical cavity using a far-detuned standing-wave dipole trap (2). b, An impinging weak coherent pulse (3) with arbitrary polarization is converted into an atomic spin excitation using a pi-polarized pump laser (4). c, This maps the photonic polarization qubit onto a long-lived superposition of the ground states of the atom. d, After a variable storage time, the polarization qubit is retrieved by the production of a single photon (5).

The trick here is first to find an atom with the suitable two-level state that will absorb photons in the right way and second, to find a way to force the photon to give up its qubit to the atom.

It turns out that rubidium has the just right energy levels. Specht and co force the atom and photon to interact by trapping them in a high quality mirrored cavity in which the photon can enter but not easily escape. It then rebounds inside until it gives up its goods to the atom.

To accept the qubit, the atom first has to be placed in the right state by a weak laser beam. A second laser beam later forces the atom to spit out the qubit in the form of an identical polarised photon.

The result is a single atom memory that can read, store and write quantum information.

The notion that a single atom could be used as a storage device is one that I first encountered while reading science fiction. In his 1951 novel Between Planets, Robert Heinlein writes about a molecule matrix:

"It is theoretically possible to have a matrix in which each individual molecule has a meaning - as they do in the memory cells of your brain. If we had such subtlety, we could wrap your Encyclopedia Britannica into the head of a pin - it would be the head of that pin..."
(Read more about Heinlein's molecule matrix)

ReadmTechnology Review for more details.

Scroll down for more stories in the same category. (Story submitted 3/15/2011)

Follow this kind of news @Technovelgy.

| Email | RSS | Blog It | Stumble | del.icio.us | Digg | Reddit |

Would you like to contribute a story tip? It's easy:
Get the URL of the story, and the related sf author, and add it here.

Comment/Join discussion ( 1 )

Related News Stories - (" Computer ")

String Art Courtesy Of Robot Artist
The number of different ways to span a thread between a larger number of hooks is astronomical.

Tetraplegics Dominate Avatar Races
Well, just speaking brain-to-computer...

IBM's Grain Of Sand Computer
'Our ancestors... thought to make the very sand beneath their feet intelligent...' - Stanislaw Lem, 1965.

Can An Entire Brain Be Simulated In A Computer?
'The miles of relays and photocells had given way to the spongy globe of platinum iridium about the size of the human brain.' - Isaac Asimov, 1941.

 

Google
  Web TechNovelgy.com   

Technovelgy (that's tech-novel-gee!) is devoted to the creative science inventions and ideas of sf authors. Look for the Invention Category that interests you, the Glossary, the Invention Timeline, or see what's New.

 

 

 

 

 

Current News

Spicy Tomatoes Created With Genetic Engineering
How about mashed potatoes and brown gravy?

Driverless Hotel Rooms Predicted In 1828
'Did you never see a moving house before?'

Yandex Self-Driving Taxi Is Very Smooth
'The big car was slowing down, its computer brain sensing an exit ahead.'

Shrimp Actually Made Of Algae Is A New Wave Food
Bring in that crop algae.

Cosplay Style Wings Could Work On Moon
'They're lovely! - titanalloy struts as light and strong as bird-bones...'

Tesla Model 3 Has Outside Speaker Grille
Robert Heinlein does it again.

Arizona Luddites Attack Self-Driving Vehicles
'Trucks don't drive by themselves...' Or do they?

Organaut! Russians 3D Print Living Tissue In Space
'For a while your colonists will have to come up [to orbit] to the Hospital...'

WINE Spacecraft To Extract Water From Asteroids
'Yes, strangely enough there was still sufficient water beneath the surface of Vesta.'

Japanese Swordsmiths Take On Asteroids
'... a tiny, rocket-powered projectile, drove towards the mysterious bulk.'

Saturn's Rings To Vanish, Let's Mine Them While We Can
'...the valuable shards of what had once been satellites.'

Humans Could Take Up A LOT Less Space
We'd have a lot more room for gardening...

Implosion Fabrication Shrinks 3D Objects To Nanoscale
'Carter had watched miniaturization a hundred times...'

GMO Houseplant Cleans Your Air
Removes compounds too small to be captured by a HEPA filter.

Nova Meat Can 3D Print Your Dinner
Printing out chicken nuggets.

MIT Scientists Create 'Peek-a-Boo Prober' From Jetsons
Well, George, it's the latest thing.

More SF in the News Stories

More Beyond Technovelgy science news stories

Home | Glossary | Invention Timeline | Category | New | Contact Us | FAQ | Advertise |
Technovelgy.com - where science meets fiction™

Copyright© Technovelgy LLC; all rights reserved.