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

Soon, Your Tesla Will Follow You Like A Pet
'... follow him as faithfully as a well-trained hound.'

Chinese Watrix Gait Recognition Watching You Always
'... those pesky gait-recognition cameras.'

FlexPai Foldable Phone By Royole
'...A paper thin polycarbon screen unfurled.'

Oh Yes, We're Building The Rotating Tower In Dubai
'Give me an old-fashioned tetragon on a central pivot every time.'

Bioreactor Helps Legless Frogs Get Their Jump Back
'An alien drug... Used by an insect race... It can repair bones and organs. It can grow new tissue."

Xinhua AI Anchor Puts CGI Face To Automated News
'...a congeries of software agents.'

Wirewax Watching You Watch, Adjusting Your Experience
'He adjusted the n, the r and b knobs, and hopefully anticipated a turn for the better...'

LawGeex AI Beats 20 Top Lawyers
'The Law Society has strict rules on the use of pseudo-intelligent software - terrified of putting... its members out of work.'

ROAM Robotics Skiing Exoskeleton
'The real genius in the design is that you don't have to control the suit; you just wear it...'

MIT Headset Lets You Communicate Without Speaking
'The subvocal read nerve signals, letting her enter words by just beginning to will them...'

Exploring Oceans Across The Solar System
'Black liquid flashed past the turbotís infrared eyes.'

SWEEPER Robot Peter Piper Picking Peppers
'... little machines, that went from plant to plant, apparently on caterpillar tracks, cutting off the ripe fruit.'

Oil from Algae - Can It Be Done?
'We dump everything that's waste into the tanks, pump the oil off the top.'

Moving Whole Planets, Revisited
There was a lot of work done on this idea over the years.

Disney Keeps Backups Of Star Wars Franchise Actors
'She is a personality-construct, a congeries of software agents...'

Farming In Space Starts With Mycorrhiza
'The inner leaves were beginning to curl faster than the outer leaves.'

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.