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 ")

Eterni.me - To Skype With The Dead
'Nothing... left of Jeserac but a galaxy of electrons frozen in the heart of a crystal.'- Arthur C. Clarke, 1956.

Razer Project Valerie Laptop Unfurls
'A paper thin polycarbon screen unfurled silently...' - William Gibson, 1986.

Google Home Continues Implementation Of Pohl's Joymaker
'It is a transponder connecting you with the central computing facilities of the city in which you reside on a shared-time, self-programming basis.' - Frederik Pohl, 1966.

New Startup 'Improbable' To Model Our World
'A machine able literally to contain the Universe Itself...' - Stanislaw Lem, 1965.

 

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

Keith Laumer's Bolo Autonomous Tanks Right On Schedule
'I cannot lie idle under attack.'

When Computers Develop Their Own Language, Will They Talk To Us?
'The curious absent look of a robot talking on the TBR circuits - the Talk Between Robots radio...'

LipNet Reads Lips - Until Disconnected, That Is
'We'd have to cut his higher brain functions... I'm not sure what [HAL} would think about that.'

Eterni.me - To Skype With The Dead
'Nothing... left of Jeserac but a galaxy of electrons frozen in the heart of a crystal.'

Wearable MRI Is Former Occulus/Facebook Exec's New Project
'Your cephalochromoscope... that you always turn on and play when you get home...'

Ford Stratasys Infinte Build 3D Printer
'He proudly indicated his Buick... Almost as good as the original it was printed from...'

The Space Suit As Personal Spaceship
'Darn clever, these suits...'

Dune Fans! Your God Emperor Is Ready
'If one held a sandtrout in the hand, smoothing it over your skin, it formed a living glove.'

Robot Strolls Field, Examines EVERY Plant
'The great machines that did the work ... required but a few dozen men to cultivate an entire county.'

Sweden Outlaws Drones
'An eye that could not only see, but fly, roam, travel at speeds and in directions to suit its operator...'

Wear Your Self-Powered Generator
'It's basically a micro-sandwich...'

TITAN-III Spider Robot Is WAY Too Quick (Video)
'My little friends can find you wherever you go!'

Bill Gates Suggests Tax On Robots
'A worker replaced by a nubot that 'appears or pretends to be human' had to be compensated...'

Handle, New Wheeled Hopping Robot
'the hopper sprang thirty feet into the air...'

Matrix Sentinel Ancestor, The Pipe Inspector Robot From Krakow
Watch out, Keanu!

Auto-Focus Smart Glasses Have Liquid Lenses
'Hufhuf oil held in static tension by an enclosing force field within a viewing tube...'

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.