Featured Research

from universities, journals, and other organizations

Atomic clock can simulate quantum magnetism

Date:
August 8, 2013
Source:
National Institute of Standards and Technology (NIST)
Summary:
Researchers have for the first time used an atomic clock as a quantum simulator, mimicking the behavior of a different, more complex quantum system. All but the smallest, most trivial quantum systems are too complicated to simulate on classical computers, hence the interest in quantum simulators to understand the quantum mechanical behavior of exotic materials such as high-temperature superconductors.

This is an artist's conception of interactions among atoms in JILA's strontium atomic clock during a quantum simulation experiment. The atoms appear to all interact (indicated by the connections), leading to correlations among the atoms' spins (indicated by arrows), according to patterns JILA scientists found in collective spin measurements. The interacting atoms might be harnessed to simulate other quantum systems such as magnetic materials.
Credit: Ye group and Brad Baxley, JILA

Researchers at JILA have for the first time used an atomic clock as a quantum simulator, mimicking the behavior of a different, more complex quantum system.

Atomic clocks now join a growing list of physical systems that can be used for modeling and perhaps eventually explaining the quantum mechanical behavior of exotic materials such as high-temperature superconductors, which conduct electricity without resistance. All but the smallest, most trivial quantum systems are too complicated to simulate on classical computers, hence the interest in quantum simulators. Sharing some of the features of experimental quantum computers -- a hot research topic -- quantum simulators are "special purpose" devices designed to provide insight into specific challenging problems.

JILA is operated jointly by the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder.

As described in the Aug. 9 issue of Science, the JILA experiment was performed with an atomic clock made of about 2,000 neutral strontium atoms trapped in intersecting laser beams. The researchers were surprised to discover that, under certain conditions, the clock atoms interact like atoms in magnetic materials.

"This was completely unexpected," JILA/NIST Fellow Jun Ye says. "We were not looking for this at all, we were just naively trying to understand the particle interactions as part of our effort to further improve the clock. We were pleasantly surprised to find we can now use a clock as a powerful quantum apparatus to study magnetic spin interactions."

The strontium clock atoms are arranged like a stack of 100 pancakes, each containing about 20 atoms. Normally the atoms react individually to red laser pulses, switching between two energy levels. But researchers discovered the atoms also can interact with each other, first in pairs and eventually all together. Until now researchers were trying to eliminate these interactions, which are undesirable in atomic clocks but they can turn into a powerful feature for a quantum simulator.

Strontium atoms have two energy levels used for clock purposes, each with a particular configuration of electrons. In the JILA simulation, all the atoms start out at the same energy level with the same electron configuration, also called a spin-down state. A quick pulse from a very stable red laser places all the atoms in a "superposition" of spins pointing both up and down at the same time. The possibility of superposition is one of the most notable features of the quantum world. When the laser is turned off, the atoms start to interact. One second later another pulse from the same laser hits the atoms to prepare them for collective spin measurement, and then a different laser measures, based on any detected fluorescence, the final spin states of all the atoms.

In the world of classical physics such measurements would have definite results, without any "noise," or uncertainty. However, in the quantum world a spin measurement usually has a random amount of noise. In the JILA experiment, correlations appear over time between the noise patterns of some of the atoms' spins. Ye says these correlations suggest the atoms become entangled, another unusual quantum feature that links the properties of separated particles. JILA researchers have not yet performed the definitive test proving entanglement, however.

JILA theorist Ana Maria Rey helped to explain what Ye's experimental team observed. For small numbers of particles, about 30 atoms, Rey calculated that the clock atom interactions obey mathematical formulas similar to those describing the behavior of electrons in magnetic materials. But if more atoms are included, classical calculations would not keep up with the experimental results. In the future the JILA team hopes to perform more complicated simulations while continuing to develop a theory explaining the findings.


Story Source:

The above story is based on materials provided by National Institute of Standards and Technology (NIST). Note: Materials may be edited for content and length.


Journal Reference:

  1. M. J. Martin, M. Bishof, M. D. Swallows, X. Zhang, C. Benko, J. von-Stecher, A. V. Gorshkov, A. M. Rey, J. Ye. A Quantum Many-Body Spin System in an Optical Lattice Clock. Science, 2013; 341 (6146): 632 DOI: 10.1126/science.1236929

Cite This Page:

National Institute of Standards and Technology (NIST). "Atomic clock can simulate quantum magnetism." ScienceDaily. ScienceDaily, 8 August 2013. <www.sciencedaily.com/releases/2013/08/130808142132.htm>.
National Institute of Standards and Technology (NIST). (2013, August 8). Atomic clock can simulate quantum magnetism. ScienceDaily. Retrieved August 28, 2014 from www.sciencedaily.com/releases/2013/08/130808142132.htm
National Institute of Standards and Technology (NIST). "Atomic clock can simulate quantum magnetism." ScienceDaily. www.sciencedaily.com/releases/2013/08/130808142132.htm (accessed August 28, 2014).

Share This




More Matter & Energy News

Thursday, August 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Chinese Researchers Might Be Creating Supersonic Submarine

Chinese Researchers Might Be Creating Supersonic Submarine

Newsy (Aug. 26, 2014) Chinese researchers have expanded on Cold War-era tech and are closer to building a submarine that could reach the speed of sound. Video provided by Newsy
Powered by NewsLook.com
Breakingviews: India Coal Strained by Supreme Court Ruling

Breakingviews: India Coal Strained by Supreme Court Ruling

Reuters - Business Video Online (Aug. 26, 2014) An acute coal shortage is likely to be aggravated as India's supreme court declared government coal allocations illegal, says Breakingviews' Peter Thal Larsen. Video provided by Reuters
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