Featured Research

from universities, journals, and other organizations

Trapping giant Rydberg atoms for faster quantum computers

Date:
May 7, 2010
Source:
University of Michigan
Summary:
In an achievement that could help enable fast quantum computers, physicists have built a better Rydberg atom trap. Rydberg atoms are highly excited, nearly-ionized giants that can be thousands of times larger than their ground-state counterparts.

An artist's interpretation of Rydberg atom trapping in an optical lattice.
Credit: Kelly Younge

In an achievement that could help enable fast quantum computers, University of Michigan physicists have built a better Rydberg atom trap. Rydberg atoms are highly excited, nearly-ionized giants that can be thousands of times larger than their ground-state counterparts.

As a result of their size, interactions between Rydberg atoms can be roughly a million times stronger than between regular atoms. This is why they could serve as faster quantum circuits, said Georg Raithel, associate chair and professor in the Department of Physics. Quantum computers could solve problems too complicated for conventional computers. Many scientists believe that the future of computation lies in the quantum realm.

A paper on this research is published in the current edition of Physical Review Letters. The work will be presented at the American Physical Society's Division of Atomic, Molecular and Optical Physics meeting in late May.

Raithel's team trapped the atoms in what's called an optical lattice -- a crate made of interfering laser beams.

"The optical lattice is better than any other Rydberg atom trap for quantum information processing or high-precision spectroscopy," Raithel said. "Compared with other traps, optical lattices minimize energy level shifts in the atoms, which is important for these applications."

Raithel and physics doctoral students Kelly Younge and Sarah Anderson started with ground-state atoms of the soft metal rubidium. At room temperature, the atoms whiz around at the speed of sound, about 300 meters per second. The researchers hit them with lasers to cool and slow them to 10 centimeters per second.

"That's about the speed of a mosquito," Younge said. "Cooling lasers combined with a magnetic field allows us to trap the ground-state atoms. Then we excite the atoms into Rydberg states."

In a rubidium atom, just one electron occupies the outer valence shell. With precisely tuned lasers, the researchers excited this electron so that it moved 100 times farther away from the nucleus of the atom, which classified it as a Rydberg atom. That valence electron in this case is so far away from the nucleus that it behaves almost as if it's a free electron.

To trap the Rydberg atoms, the researchers took advantage of what's called the "ponderomotive force" that allows them to secure a whole atom by holding fast to one electron -- the sole valence shell particle in the rubidium Rydberg atoms. The optical lattice, formed with intense, interfering laser beams, is what provides the ponderomotive force.

"The laser field holds on to the electron, which behaves almost as if it were free, but the residual weak atomic binding force still holds the atom together. In effect, the entire atom is trapped by the lasers," Raithel said.

The physicists used a technique called "microwave spectroscopy," to determine how the lattice affected the Rydberg atoms, and in general how the atoms behaved in the trap.

"Essentially, we could track the motion of the atoms during the experiment. We could tell if the atoms were sitting in the bottom of a well in the electromagnetic field, or if they were roaming over many wells. In this way, we could optimize the performance of the trap," Younge said.

The paper is called "State-dependent Energy Shifts of Rydberg Atoms in a Ponderomotive Optical Lattice."

This research is funded by the National Science Foundation and the National Defense Science and Engineering Graduate Fellowship Program.


Story Source:

The above story is based on materials provided by University of Michigan. Note: Materials may be edited for content and length.


Journal Reference:

  1. K. C. Younge, B. Knuffman, S. E. Anderson, G. Raithel. State-Dependent Energy Shifts of Rydberg Atoms in a Ponderomotive Optical Lattice. Physical Review Letters, 2010; 104 (17): 173001 DOI: 10.1103/PhysRevLett.104.173001

Cite This Page:

University of Michigan. "Trapping giant Rydberg atoms for faster quantum computers." ScienceDaily. ScienceDaily, 7 May 2010. <www.sciencedaily.com/releases/2010/05/100506141638.htm>.
University of Michigan. (2010, May 7). Trapping giant Rydberg atoms for faster quantum computers. ScienceDaily. Retrieved April 20, 2014 from www.sciencedaily.com/releases/2010/05/100506141638.htm
University of Michigan. "Trapping giant Rydberg atoms for faster quantum computers." ScienceDaily. www.sciencedaily.com/releases/2010/05/100506141638.htm (accessed April 20, 2014).

Share This



More Matter & Energy News

Sunday, April 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Why Did Nike Fire Most Of Its Nike FuelBand Team?

Why Did Nike Fire Most Of Its Nike FuelBand Team?

Newsy (Apr. 19, 2014) Nike fired most of its Digital Sport hardware team, the group behind Nike's FuelBand device. Could Apple or an overcrowded market be behind layoffs? Video provided by Newsy
Powered by NewsLook.com
Small Reactors Could Be Future of Nuclear Energy

Small Reactors Could Be Future of Nuclear Energy

AP (Apr. 17, 2014) After the Fukushima nuclear disaster, the industry fell under intense scrutiny. Now, small underground nuclear power plants are being considered as the possible future of the nuclear energy. (April 17) Video provided by AP
Powered by NewsLook.com
Horseless Carriage Introduced at NY Auto Show

Horseless Carriage Introduced at NY Auto Show

AP (Apr. 17, 2014) An electric car that proponents hope will replace horse-drawn carriages in New York City has also been revealed at the auto show. (Apr. 17) Video provided by AP
Powered by NewsLook.com
Honda's New ASIMO Robot, More Human-Like Than Ever

Honda's New ASIMO Robot, More Human-Like Than Ever

AFP (Apr. 17, 2014) It walks and runs, even up and down stairs. It can open a bottle and serve a drink, and politely tries to shake hands with a stranger. Meet the latest ASIMO, Honda's humanoid robot. Duration: 00:54 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins