Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Experimentation and largest-ever quantum simulation of a disordered system explain quantum many-particle problem

15.03.2016

Using some of the largest supercomputers available, physics researchers from the University of Illinois at Urbana-Champaign have produced one of the largest simulations ever to help explain one of physics most daunting problems.

"This result was a fantastic collaboration between theory and experiment," explained Physics Professor Brian DeMarco, whose group led the experimental phase of the study.


Figure illustrates puddles of localized quasi-condensates found using a quantum Monte Carlo simulation of trapped atoms in a disordered lattice. Individual puddles, consisting of 10-20 particles each, are incoherent relative to each other. The Bose glass is composed of these puddle-like structures.

Credit: Ushnish Ray, University of Illinois

"One of the grandest and most impactful frontiers of physics is the quantum many-particle problem. We do not understand very well what happens when many quantum particles come together and interact with each other. This problem spans some of the largest scales in the universe, like understanding the nuclear matter in neutron stars, to the smallest, such as electron transport in photosynthesis and the quarks and gluons inside a proton."

DeMarco's group experiments with atoms gases cooled to just billionths of a degree above absolute zero temperature in order to experimentally simulate models of materials such as high-temperature superconductors. In these experiments, the atoms play the role of electrons in a material, and the analog of material parameters (like disorder) are completely controlled and known and can be changed every 90-second experimental cycle. Measurements on the atoms are used to expose new physics and test theories.

"In most cases, we lack predictive power, because these problems are not readily computable -- a classical computer requires exponentially costly resources to simulate many quantum systems," added David Ceperley, a professor of physics whose team developed the companion simulation. "A key example of this problem with practical challenges lies with materials such as high-temperature superconductors. Even armed with the chemical composition and structure of these materials, it is almost impossible to predict today at what temperature they will super-conduct."

The different approaches to attacking a particularly important quantum many-particle problem by DeMarco's and Ceperley's groups came together in a new result published in Nature Physics. In their paper, "Probing the Bose glass-superfluid transition using quantum quenches of disorder," Carolyn Meldgin from DeMarco's group and Ushnish Ray from Ceperley's team share a new understanding of how disorder in a quantum material gives rise to an exotic quantum state called a Bose glass.

"A Bose glass is a strange and poorly understood insulator that can occur when disorder is added to a superfluid or superconductor," Meldgin said. In her experiments, Meldgin was able to use optical disorder to induce a Bose glass, and Ray exactly simulated the experiment using the Titan supercomputer.

In this work, Ceperley's group achieved the largest scale computer simulations possible of a disordered quantum many-particle system on the biggest supercomputers in existence. These computer simulations were able to simulate relatively large numbers of particles, such as the 30,000 atoms used in DeMarco's experiments.

Together, Meldgin and Ray were able to show something startling--that a dynamic probe in the experiment connects to the equilibrium computer simulations.

"In both cases, the same amount of disorder is required to turn a superfluid into a Bose-glass," Ray stated. "This result is critically important to our understanding of disordered quantum materials, which are ubiquitous, since disorder is difficult to avoid. It also has important implications for quantum annealers, like the D-Wave Systems device."

Brian DeMarco | EurekAlert!

More articles from Materials Sciences:

nachricht Fast flowing heat in layered material heterostructures
18.12.2017 | Graphene Flagship

nachricht One in 5 materials chemistry papers may be wrong, study suggests
15.12.2017 | Georgia Institute of Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Error-free into the Quantum Computer Age

A study carried out by an international team of researchers and published in the journal Physical Review X shows that ion-trap technologies available today are suitable for building large-scale quantum computers. The scientists introduce trapped-ion quantum error correction protocols that detect and correct processing errors.

In order to reach their full potential, today’s quantum computer prototypes have to meet specific criteria: First, they have to be made bigger, which means...

Im Focus: Search for planets with Carmenes successful

German and Spanish researchers plan, build and use modern spectrograph

Since 2016, German and Spanish researchers, among them scientists from the University of Göttingen, have been hunting for exoplanets with the “Carmenes”...

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

The body's street sweepers

18.12.2017 | Life Sciences

Fast flowing heat in layered material heterostructures

18.12.2017 | Materials Sciences

Life on the edge prepares plants for climate change

18.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>