Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International

Wikipedia Affiliate Button

Home > Press > Single atom stores quantum information: A powerful quantum computer could be designed with an incredibly tiny memory

One single atom as data memory: Researchers at the Max Planck Institute of Quantum Optics wrote quantum information into a rubidium atom between two mirrors and read it out again after a certain storage time.

 Andreas Neuzner
One single atom as data memory: Researchers at the Max Planck Institute of Quantum Optics wrote quantum information into a rubidium atom between two mirrors and read it out again after a certain storage time.

Andreas Neuzner

Abstract:
A data memory can hardly be any smaller: researchers working with Gerhard Rempe at the Max Planck Institute of Quantum Optics in Garching have stored quantum information in a single atom. The researchers wrote the quantum state of single photons, i.e. particles of light, into a rubidium atom and read it out again after a certain storage time. This technique can be used in principle to design powerful quantum computers and to network them with each other across large distances.

Single atom stores quantum information: A powerful quantum computer could be designed with an incredibly tiny memory

Munich, Germany | Posted on May 3rd, 2011

Quantum computers will one day be able to cope with computational tasks in no time where current computers would take years. They will take their enormous computing power from their ability to simultaneously process the diverse pieces of information which are stored in the quantum state of microscopic physical systems, such as single atoms and photons. In order to be able to operate, the quantum computers must exchange these pieces of information between their individual components. Photons are particularly suitable for this, as no matter needs to be transported with them.

Particles of matter however will be used for the information storage and processing. Researchers are therefore looking for methods whereby quantum information can be exchanged between photons and matter. Although this has already been done with ensembles of many thousands of atoms, physicists at the Max Planck Institute of Quantum Optics in Garching have now proved that quantum information can also be exchanged between single atoms and photons in a controlled way.

Using a single atom as a storage unit has several advantages - the extreme miniaturization being only one, says Holger Specht from the Garching-based Max Planck Institute, who was involved in the experiment. The stored information can be processed by direct manipulation on the atom, which is important for the execution of logical operations in a quantum computer. "In addition, it offers the chance to check whether the quantum information stored in the photon has been successfully written into the atom without destroying the quantum state," says Specht. It is thus possible to ascertain at an early stage that a computing process must be repeated because of a storage error.

The fact that no one had succeeded until very recently in exchanging quantum information between photons and single atoms was because the interaction between the particles of light and the atoms is very weak. Atom and photon do not take much notice of each other, as it were, like two party guests who hardly talk to each other, and can therefore exchange only a little information. The researchers in Garching have enhanced the interaction with a trick. They placed a rubidium atom between the mirrors of an optical resonator, and then used very weak laser pulses to introduce single photons into the resonator. The mirrors of the resonator reflected the photons to and fro several times, which strongly enhanced the interaction between photons and atom. Figuratively speaking, the party guests thus meet more often and the chance that they talk to each other increases.

The photons carried the quantum information in the form of their polarization. This can be left-handed (the direction of rotation of the electric field is anti-clockwise) or right-handed (clock-wise). The quantum state of the photon can contain both polarizations simultaneously as a so-called superposition state. In the interaction with the photon the rubidium atom is usually excited and then loses the excitation again by means of the probabilistic emission of a further photon. The Garching-based researchers did not want this to happen. On the contrary, the absorption of the photon was to bring the rubidium atom into a definite, stable quantum state. The researchers achieved this with the aid of a further laser beam, the so-called control laser, which they directed onto the rubidium atom at the same time as it interacted with the photon.

####

For more information, please click here

Contacts:
Prof. Dr. Dr. habil. Gerhard Rempe
Max Planck Institute of Quantum Optics, Garching
Phone: +49 89 32905-701
Fax: +49 89 32905-311
Email:

Copyright © Max Planck Institute of Quantum Optics

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Drilling speed increased by 20% yet another upgrade in the oil & gas sector made possible by graphene nanotubes January 15th, 2019

Chirality in 'real-time' January 14th, 2019

New materials could help improve the performance of perovskite solar cells January 11th, 2019

Media invited to open meeting on the future of quantum technology held at RIT Jan. 23-25: Leaders from NASA, NSF, NIST and Sandia National Laboratory to attend January 11th, 2019

Quantum Computing

Media invited to open meeting on the future of quantum technology held at RIT Jan. 23-25: Leaders from NASA, NSF, NIST and Sandia National Laboratory to attend January 11th, 2019

Spintronics 'miracle material' put to the test: Physicists build devices using mineral perovskite January 11th, 2019

DNA design that anyone can do: Computer program can translate a free-form 2-D drawing into a DNA structure January 4th, 2019

Quantum chemistry on quantum computers: A quantum algorithm for tracking complex chemical reactions with neither performing demanding post-Hartree-Fock calculations nor exponential time explosion January 4th, 2019

Discoveries

Chirality in 'real-time' January 14th, 2019

New materials could help improve the performance of perovskite solar cells January 11th, 2019

Spintronics 'miracle material' put to the test: Physicists build devices using mineral perovskite January 11th, 2019

Cartilage could be key to safe 'structural batteries' January 11th, 2019

Announcements

Drilling speed increased by 20% yet another upgrade in the oil & gas sector made possible by graphene nanotubes January 15th, 2019

Chirality in 'real-time' January 14th, 2019

Spintronics 'miracle material' put to the test: Physicists build devices using mineral perovskite January 11th, 2019

Cartilage could be key to safe 'structural batteries' January 11th, 2019

Quantum nanoscience

Spintronics 'miracle material' put to the test: Physicists build devices using mineral perovskite January 11th, 2019

Quantum chemistry on quantum computers: A quantum algorithm for tracking complex chemical reactions with neither performing demanding post-Hartree-Fock calculations nor exponential time explosion January 4th, 2019

Boffins manage to keep graphene qubits 'quantum coherent' for all of 55... nanoseconds: Doesn't sound very long, but it could have big implications for quantum computing January 3rd, 2019

Researchers make liquid crystals do the twist: UMD engineers and scientists measure previously unexamined tiny force December 21st, 2018

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project