Such light-tweaked atoms can be used as proxies to study important phenomena that would be difficult or impossible to study in other contexts. Their most recent work, appearing in Science,* demonstrates a new class of interactions thought to be important to the physics of superconductors that could be used for quantum computation.
Particle interactions are fundamental to physics, determining, for example, how magnetic materials and high temperature superconductors work. Learning more about these interactions or creating new "effective" interactions will help scientists design materials with specific magnetic or superconducting properties.
Because most materials are complicated systems, it is difficult to study or engineer the interactions between the constituent electrons. Researchers at NIST build physically analogous systems using supercooled atoms to learn more about how materials with these properties work.
"Basically, we're able to simulate these complicated systems and observe how they work in slow motion," says Ian Spielman, a physicist at NIST and fellow of the Joint Quantum Institute (JQI), a collaborative enterprise of NIST and the University of Maryland.
According to Ross Williams, a postdoctoral researcher at NIST, cold atom experiments are good for studying many body systems because they offer a high degree of control over position and behavior of the atoms.
"First, we trap rubidium-87 atoms using magnetic fields and cool them down to 100 nanokelvins," says Williams. "At these temperatures, they become what's known as a Bose-Einstein condensate. Cooling the atoms this much makes them really sluggish, and once we see that they are moving slowly enough, we use lasers to 'dress' the atoms, or mix together different energy states within them. Once we have dressed the atoms, we split the condensate, collide the two parts, and then see how they interact."
According to Williams, without being laser-dressed, simple, low-energy interactions dominate how the atoms scatter as they come together. While in this state, the atoms bang into each other and scatter to form a uniform sphere that looks the same from every direction, which doesn't reveal much about how the atoms interacted.
When dressed, however, the atoms tended to scatter in certain directions and form interesting shapes indicative of the influence of new, more complicated interactions, which aren't normally seen in ultracold atom systems. The ability to induce them allows researchers to explore a whole new range of exciting quantum phenomena in these systems.
While the researchers used rubidium atoms, which are bosons, for this experiment, they are modifying the scheme to study ultracold fermions, a different species of particle. The group hopes to find evidence of the Majorana fermion, an enigmatic, still theoretical kind of particle that is involved in superconducting systems important to quantum computation.
"A lot of people are looking for the Majorana fermion," says Williams. "It would be great if our approach helped us to be the first."
For more details, see the JQI news announcement, "The Impact of Quantum Matter" at http://jqi.umd.edu/news/291-the-impact-of-quantum-matter.html.
View an animation of the atom interactions on the NIST YouTube channel at http://www.youtube.com/watch?v=cRiLCTnFRdM
* R.A. Williams, L.J. LeBlanc, K. Jiménez-García, M.C. Beeler, A.R. Perry, W.D. Phillips, I.B. Spielman. Synthetic Partial Waves in Ultracold Atomic Collisions . Science Express, 8 December 2011
Mark Esser | EurekAlert!
Further reports about: > Atoms > Bose-Einstein condensate > Majorana > NIST > Quantum > atoms scatter > body systems > high temperature superconductors work > magnetic field > magnetic material > quantum computation > quantum phenomena > rubidium-87 atoms > superconducting properties > ultracold atom systems
NASA's Fermi catches gamma-ray flashes from tropical storms
25.04.2017 | NASA/Goddard Space Flight Center
DGIST develops 20 times faster biosensor
24.04.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
25.04.2017 | Physics and Astronomy
25.04.2017 | Materials Sciences
25.04.2017 | Life Sciences