Featured Research

from universities, journals, and other organizations

Atoms Don't Dance The 'Bose Nova': Realization Of An Excited, Strongly Correlated Many-body Phase

Date:
September 5, 2009
Source:
University of Innsbruck
Summary:
An Austrian research group has investigated how ultracold quantum gases behave in lower spatial dimensions. They successfully realized an exotic state, where, due to the laws of quantum mechanics, atoms align along a one-dimensional structure. A stable many-body phase with new quantum mechanical states is thereby produced even though the atoms are usually strongly attracted which would cause the system to collapse.

Hanns-Christoph Naegerl's research group has investigated how ultracold quantum gases behave in lower spatial dimensions. They successfully realized an exotic state, where, due to the laws of quantum mechanics, atoms align along a one-dimensional structure. A stable many-body phase with new quantum mechanical states is thereby produced even though the atoms are usually strongly attracted which would cause the system to collapse.

Related Articles


The scientists report on their findings in the scientific journal Science.

Interactions are considerably more drastic in low-dimensional systems than in three-dimensional ones. Thus, physicists take a special interest in these systems. In physics zero-dimensional quantum dots, two-dimensional quantum wells and also one-dimensional quantum wires are known. The latter are spatial potential structures, where carriers can move only one-dimensionally. Whereas quantum dots and wells can be realized and analyzed relatively easily, it is much harder to investigate quantum wires in solid-state bodies.

Naegerl's research group of the Institute for Experimental Physics of the University of Innsbruck has now tried something totally different: In a cloud of ultracold atoms they realized one-dimensional structures and thoroughly analyzed their properties.

Surprising observation

In a vacuum chamber the physicists produced a Bose-Einstein condensate with approx. 40,000 ultracold cesium atoms. With two laser beams they generated an optical lattice, where the atoms were confined to vertical one-dimensional structures with up to 15 atoms aligned in each tube. The laser beams prevent the atoms from breaking ranks or changing place with each other.

Using a magnetic field, the scientists could tune the interaction between the atoms: "By increasing the interaction energy between the atoms (attraction interaction), the atoms start coming together and the structure quickly decays," Naegerl explains what is called among experts the "Bosenova" effect. "By minimizing the interaction energy, the atoms repel each other (repulsive interaction), align vertically and regularly along a one-dimensional structure and the system is stable."

If the interactions are switched from strongly repulsive to strongly attractive, a surprising effect can be observed. "We thereby achieve an exotic, gas-like phase, where the atoms are excited and correlated but do not come together and a 'Bosenova' effect is absent," Naegerl says. The phase was diagnosed by compressing the quantum gas and measuring its stiffness.

"However, this excited many-body phase can only be realized by a detour via repulsive interaction. This phase was predicted four years ago and we have now been able to realize it experimentally for the first time," an excited Elmar Haller says. He is first author of the research paper, which is now published in the renowned scientific journal Science. Currently, research on low-dimensional structures receives a lot of attention internationally and it may help to better understand the functioning of high-temperature superconductors.

Cold atoms as an ideal field of experimentation

"Ultracold quantum gases offer a big advantage: They can be isolated against the environment quite well," Naegerl explains. "Moreover, in our experiment we can practically rule out defects we often find in solid-state bodies."

With this successful experiment the Innsbruck quantum physicists found an ideal experimental setup to further study the properties of quantum wires. Naegerl's team of scientists clearly benefits from the long standing and successful research on ultracold atoms and molecules by another Innsbruck group of physicists: the research group led by Wittgenstein laureate Prof. Rudolf Grimm, which has already assumed a leading role internationally.

In addition to producing the first Bose-Einstein condensates using cesium atoms and molecules, the scientists also observed exotic states such as the Efimov-state and repulsive quantum pairs experimentally for the first time worldwide.

"The research work of Hanns-Christoph Naegerl and his team once more underlines the international significance of our research projects," Rudolf Grimm says.

The experimental physicists of the research project on quantum wires also benefited from a very close cooperation with the theoretical physicists of the quantum physics stronghold in Innsbruck. The project of START-awardee Hanns-Christoph Naegerl is funded by the Austrian Science Funds and the European Union.


Story Source:

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


Cite This Page:

University of Innsbruck. "Atoms Don't Dance The 'Bose Nova': Realization Of An Excited, Strongly Correlated Many-body Phase." ScienceDaily. ScienceDaily, 5 September 2009. <www.sciencedaily.com/releases/2009/09/090903163850.htm>.
University of Innsbruck. (2009, September 5). Atoms Don't Dance The 'Bose Nova': Realization Of An Excited, Strongly Correlated Many-body Phase. ScienceDaily. Retrieved December 19, 2014 from www.sciencedaily.com/releases/2009/09/090903163850.htm
University of Innsbruck. "Atoms Don't Dance The 'Bose Nova': Realization Of An Excited, Strongly Correlated Many-body Phase." ScienceDaily. www.sciencedaily.com/releases/2009/09/090903163850.htm (accessed December 19, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Friday, December 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
3D Printed Cookies Just in Time for Christmas

3D Printed Cookies Just in Time for Christmas

Reuters - Innovations Video Online (Dec. 18, 2014) A tech company in Spain have combined technology with cuisine to develop the 'Foodini', a 3D printer designed to print the perfect cookie for Santa. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
First Etihad Superjumbo Flight in December

First Etihad Superjumbo Flight in December

AFP (Dec. 18, 2014) The first flight of Etihad Airways' long-awaited Airbus A380 superjumbo will take place later in December, the Abu Dhabi carrier said Thursday, also announcing its first Boeing 787 Dreamliner route. Duration: 01:09 Video provided by AFP
Powered by NewsLook.com
Ford Expands Air Bag Recall Nationwide

Ford Expands Air Bag Recall Nationwide

Newsy (Dec. 18, 2014) The automaker added 447,000 vehicles to its recall list, bringing the total to more than 502,000. Video provided by Newsy
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:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

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