Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Quantum computing with individual atoms

13.06.2002


Researchers at the University of Michigan’s Center for Optical Coherent and Ultrafast Science (FOCUS) and Department of Physics have reported the first demonstration of laser-cooling of individual trapped atoms of different species. This may be an important step in the construction of a future "quantum computer," in which quantum superpositions of inputs are processed simultaneously in a single device. Trapped atoms offer one of the only realistic approaches to precisely controlling the complex quantum systems underlying a quantum computer.



The demonstration is described in the April 2002 issue of Physical Review in an article, "Sympathetic Cooling of Trapped Cd+ Isotopes," by Boris B. Blinov, Louis Deslauriers, Patricia Lee, Martin J. Madsen, Russ Miller, and Christopher Monroe. Partially based on these results, Monroe has proposed a new "Architecture for a Large-Scale Ion-Trap Quantum Computer," with co-authors David Kielpinski (MIT) and David Wineland (National Institute of Standards and Technology), in the June 13 issue of the journal Nature.

Interest in quantum computing has mushroomed in the last decade as its potential for efficiently solving difficult computing tasks, like factoring large numbers and searching large databases, has become evident. Encryption and its obverse, codebreaking, are just two of the applications envisioned for quantum computing if and when it becomes a practical technology. Quantum computation has captured the imagination of the scientific community, recasting some of the most puzzling aspects of quantum physics---once pondered by Einstein, Schroedinger and others---in the context of advancing computer science. "Right now, there’s a lot of black magic involved in understanding what makes a quantum computer tick and how to actually build one," Monroe said. "Many physicists doubt we’ll ever be able to do it, but I’m an optimist. We may not get there for decades, but given enough time and resources---and failing unexpected roadblocks like the failure of quantum mechanics---we should be able to design and build a useable quantum computer. It’s a risky business, but the potential payoff is huge."


In their experiment, the Michigan researchers used electric fields to confine a crystal of exactly two Cd+ atoms of different isotopes. They were able to cool the single 112Cd+ atom to a chilly 0.001 degree Celsius above absolute zero through direct laser cooling of the neighboring 114Cd+ atom. Laser cooling of this "refrigerator atom" removes unwanted motion in the atom crystal without affecting the internal state of the other atom. This is an important step toward scaling a trapped atom computer, where "qubits" of information are stored in the quantum states within the individual atoms.

The architecture proposed in the Nature article describes a "quantum charge-coupled device" (QCCD) consisting of a large number of interconnected atom traps. A combination of radiofrequency (RF) and quasistatic electric fields can be used to change the operating voltages of these traps, confining a few charged atoms in each trap or shuttling them from trap to trap, and the traps can be combined to form complex structures. The cooling of multiple species demonstrated at Michigan is a key component of this broader proposal.

"This is a realistic architecture for quantum computation that is scalable to large numbers of qubits," the authors conclude. "In contrast to other proposals, all quantum state manipulations necessary for our scheme have already been experimentally tested with small numbers of atoms, and the scaling up to large numbers of qubits looks straightforward."


For more information, contact Christopher Monroe, (734) 615-9625, crmonroe@umich.edu. To learn more about FOCUS, visit http://www.umich.edu/~focuspfc/.

The University of Michigan
News Service
412 Maynard
Ann Arbor, MI 48109-1399

EDITORS: Graphics can be seen at http://www.umich.edu/%7Enewsinfo/Releases/2002/Jun02/061202.html. High-resolution versions available on request.

Judy Steeh | EurekAlert
Further information:
http://www.umich.edu/~focuspfc
http://www.umich.edu/%7Enewsinfo/Releases/2002/Jun02/061202.html

More articles from Physics and Astronomy:

nachricht Squeezing light at the nanoscale
18.06.2018 | Harvard John A. Paulson School of Engineering and Applied Sciences

nachricht The Fraunhofer IAF is a »Landmark in the Land of Ideas«
15.06.2018 | Fraunhofer-Institut für Angewandte Festkörperphysik IAF

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

Im Focus: Photoexcited graphene puzzle solved

A boost for graphene-based light detectors

Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...

Im Focus: Water is not the same as water

Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.

From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Scientists predict a new superhard material with unique properties

18.06.2018 | Materials Sciences

Squeezing light at the nanoscale

18.06.2018 | Physics and Astronomy

A sprinkle of platinum nanoparticles onto graphene makes brain probes more sensitive

15.06.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>