Through simple system studies, researchers are unearthing a new quantum state of matter

Nov 21, 2011

Researchers at the University of Pittsburgh have made advances in better understanding correlated quantum matter that could change technology as we know it, according to a study published in the Nov. 20 edition of Nature.

W. Vincent Liu, associate professor of physics in Pitt's Department of Physics and Astronomy, in with researchers from the University of Maryland and the University of Hamburg in England, has been studying topological states in order to advance computing, a method that harnesses the power of atoms and molecules for computational tasks. Through his research, Liu and his team have been studying orbital and nano-Kelvin cold atoms in optical lattices (a set of lasers) to better understand new quantum states of matter.

From that research, a surprising topological semimetal has emerged.

"We never expected a result like this based on previous studies," said Liu. "We were surprised to find that such a simple system could reveal itself as a new type of topological state—an insulator that shares the same properties as a quantum Hall state in solid materials."

Since the discovery of the quantum Hall effect by Klaus Van Klitzing in 1985, researchers like Liu have been particularly interested in studying topological states of matter, that is, properties of space unchanged under continuous deformations or distortions such as bending and stretching. The quantum Hall effect proved that when a magnetic field is applied perpendicular to the direction a current is flowing through a metal, a voltage is developed in the third perpendicular direction. Liu's work has yielded similar yet remarkably different results.

"This new is very reminiscent of quantum Hall edge states," said Liu. "It shares the same surface appearance, but the mechanism is entirely different: This Hall-like state is driven by interaction, not by an applied magnetic field."

Liu and his collaborators have come up with a specific experimental design of optical lattices and tested the topological semimetal state by loading very onto this "checkerboard" lattice. Generally, these tests result in two or more domains with opposite orbital currents; therefore the angular momentum remains at zero. However, in Liu's study, the atoms formed global rotations, which broke time-reversal symmetry: The momentum was higher, and the currents were not opposite.

"By studying these orbital degrees of freedom, we were able to discover liquid matter that had no origins within solid-state electronic materials," said Liu.

Liu says this liquid matter could potentially lead toward topological quantum computers and new quantum devices for topological quantum telecommunication. Next, he and his team plan to measure quantities for a cold-atom system to check these predicted quantum-like properties.

Explore further: Team finds elusive quantum transformations near absolute zero

Provided by University of Pittsburgh

3.1 /5 (18 votes)

Related Stories

Exotic quantum states: A new research approach

Oct 03, 2011

(PhysOrg.com) -- Theoretical physicists of the University of Innsbruck have formulated a new concept to engineer exotic, so-called topological states of matter in quantum mechanical many-body systems. They ...

Physicists move one step closer to quantum computer

Oct 04, 2011

Rice University physicists have created a tiny "electron superhighway" that could one day be useful for building a quantum computer, a new type of computer that will use quantum particles in place of the digital ...

Cross-Dressing Rubidium May Reveal Clues for Exotic Computing

Feb 25, 2009

(PhysOrg.com) -- Neutral atoms--having no net electric charge--usually don't act very dramatically around a magnetic field. But by “dressing them up” with light, researchers at the Joint Quantum Institute, a collaborative ...

Topological insulators take two steps forward

Aug 10, 2010

A team of researchers from the Stanford Institute of Materials and Energy Science, a joint institute of the Department of Energy's SLAC National Accelerator Laboratory and Stanford University, and their international ...

Recommended for you

Physicists design zero-friction quantum engine

16 hours ago

(Phys.org) —In real physical processes, some energy is always lost any time work is produced. The lost energy almost always occurs due to friction, especially in processes that involve mechanical motion. ...

Fluid mechanics suggests alternative to quantum orthodoxy

Sep 12, 2014

The central mystery of quantum mechanics is that small chunks of matter sometimes seem to behave like particles, sometimes like waves. For most of the past century, the prevailing explanation of this conundrum ...

The sound of an atom has been captured

Sep 11, 2014

Researchers at Chalmers University of Technology are first to show the use of sound to communicate with an artificial atom. They can thereby demonstrate phenomena from quantum physics with sound taking on ...

The quantum revolution is a step closer

Sep 11, 2014

A new way to run a quantum algorithm using much simpler methods than previously thought has been discovered by a team of researchers at the University of Bristol. These findings could dramatically bring ...

User comments : 8

Adjust slider to filter visible comments by rank

Display comments: newest first

axemaster
not rated yet Nov 21, 2011
Wow, this article was almost impossible to understand, and I've done experiments with the Hall effect before. Are there any editors who look at this stuff before it goes out?
Going
not rated yet Nov 21, 2011
University of Hamburg in England?
thermodynamics
not rated yet Nov 21, 2011
The reason this is not understandable is that it is very poorly written. For instance they say: "The quantum Hall effect proved that when a magnetic field is applied perpendicular to the direction a current is flowing through a metal, a voltage is developed in the third perpendicular direction." That is just the Hall effect. The quantum portion of it is that the current produced is quantized (specific values) under low temperature quantum conditions. They continue to chop parts of sentences out without adding all of the content. No wonder it is hard to follow.
Drumsk8
not rated yet Nov 21, 2011
University of Hamburg is GERMANY moron writers!
rah
1 / 5 (1) Nov 21, 2011
I understand ya! This article quantum show entirely shifted unexplained. So for the first time, it can be shown (redacted)Hall effect was produced in a nano quantum entangled state without the need for any rare earth magnets or funding evaporating said Professor Liu change physics! more Tsingtao?
Angus_P__Magilicutty
not rated yet Nov 21, 2011
I agree with the above. This sounds potentially important, but isn't there diagrams or analogies or SOMETHING that could illustrate the points made here better than this?
bugmenot23
5 / 5 (2) Nov 22, 2011
Original press release @ http://www.news.p...mPhysics

NBF article @ http://nextbigfut...-of.html
Nerdyguy
not rated yet Nov 22, 2011
I understand ya! This article quantum show entirely shifted unexplained. So for the first time, it can be shown (redacted)Hall effect was produced in a nano quantum entangled state without the need for any rare earth magnets or funding evaporating said Professor Liu change physics! more Tsingtao?


More Tsingtao?" haha

And I've got a feeling that the "original" press release bugmenot23 posted has just been updated at Pitt's site after numerous complaints about how bad it was. Hard to believe they got Hamburg wrong. Given that the researchers are working together. Oh, well, maybe it was written by an English major, lol.