Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Quantum Simulator for Complex Electronic Materials

Abb./©: Univ.-Prof. Dr. Immanuel Bloch, Institut für Physik, Universität Mainz
impression of a fermiotic Mott Insulator: the two colors indicate the different spin states of the atoms
Abb./©: Univ.-Prof. Dr. Immanuel Bloch, Institut für Physik, Universität Mainz impression of a fermiotic Mott Insulator: the two colors indicate the different spin states of the atoms

Abstract:
Researchers from Mainz, Cologne and Jülich simulate complex electronic insulator with ultracold atoms in artificial crystals of light

Quantum Simulator for Complex Electronic Materials

Germany | Posted on December 5th, 2008

The design of new materials with specific properties is an important but demanding challenge in physics and chemistry. Already in 1982 Nobel Prize winner Richard P. Feynman therefore suggested to build a "quantum simulator" in order to understand and predict the properties of complex materials by simulating them using an artificial, but highly controllable quantum system. In the latest issue of the journal Science researchers from the University of Mainz, the University of Cologne and the Forschungszentrum Jülich show how to simulate the properties of electrons in a real crystal by using ultracold fermionic atoms trapped in an artificial crystal formed by interfering laser beams - a so-called optical lattice.

The researchers succeeded in demonstrating one of the most dramatic effects of the electron-electron repulsion: When the interactions between the electrons get too strong, a metal can suddenly become insulating. The resulting so-called Mott-insulator is probably the most important example of a strongly correlated state in condensed matter physics, and it is a natural starting point for the investigation of quantum magnetism. Furthermore, high temperature superconductivity is found to arise in close proximity to it. "Atoms in an optical lattice are a nearly perfect quantum simulator for electrons in a solid, as they offer a very flexible model-system in a clean and well-controlled environment," explains Ulrich Schneider from the University of Mainz.

A direct investigation of complex materials and high temperature superconductors is difficult because of the presence of disorder and many competing interactions in the real crystalline materials. "This makes it very hard to identify the role of specific interactions and, in particular, to decide whether repulsive interactions between fermions alone can explain high temperature superconductivity." In the experiment, a gas of potassium atoms is first cooled down to temperatures near absolute zero. Subsequently, an optical lattice is formed by overlapping several laser beams. To the atoms, the resulting standing-wave field appears as a regular crystal of hundreds of thousands individual micro-traps, similar to an array of optical tweezers. The ultracold atoms, which play the role of electrons in real solids, will line up at the nodes of this standing-wave field.

By investigating the behavior of the atoms under compression and increasing interaction strength, and thereby measuring their compressibility, the experimentalists led by Prof. Immanuel Bloch of the Johannes Gutenberg University Mainz have been able to controllably switch the system between metallic and insulating states of matter and find evidence for a Mott-insulating phase within the quantum gas of fermionic atoms. In such a Mott-insulating phase, the repulsive interactions between the atoms force them to order one-by-one into the regular lattice structure. The observation of the fermionic Mott-insulator in the context of optical lattices opens up a new possibility to simulate and study strongly correlated states and related phenomena. This is affirmed by the excellent agreement achieved in comparing the experiment with theoretical calculations of modern condensed matter theory performed in Cologne and Jülich, which included extensive simulations on the Jülich based supercomputer system JUGENE.

####

For more information, please click here

Contacts:
Professor Dr Immanuel Bloch
Department of Physics
Johannes Gutenberg University
D 55099 Mainz
Tel +49 6131 39-26234
Fax +49 6131 39-25179

Copyright © Johannes Gutenberg University Mainz

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Physics

A 'movie' of ultrafast rotating molecules at a hundred billion per second: A quantum wave-like nature was successfully observed in rotating nitrogen molecules July 4th, 2015

Clues to inner atomic life from subtle light-emission shifts: Hyperfine structure of light absorption by short-lived cadmium atom isotopes reveals characteristics of the nucleus that matter for high precision detection methods July 3rd, 2015

Nanospiked bacteria are the brightest hard X-ray emitters July 2nd, 2015

Producing spin-entangled electrons July 2nd, 2015

News and information

A 'movie' of ultrafast rotating molecules at a hundred billion per second: A quantum wave-like nature was successfully observed in rotating nitrogen molecules July 4th, 2015

New Biosensor Produced in Iran to Detect Effective Drugs in Cancer Treatment July 4th, 2015

Clues to inner atomic life from subtle light-emission shifts: Hyperfine structure of light absorption by short-lived cadmium atom isotopes reveals characteristics of the nucleus that matter for high precision detection methods July 3rd, 2015

Groundbreaking research to help control liquids at micro and nano scales July 3rd, 2015

Chemistry

Groundbreaking research to help control liquids at micro and nano scales July 3rd, 2015

Discoveries

A 'movie' of ultrafast rotating molecules at a hundred billion per second: A quantum wave-like nature was successfully observed in rotating nitrogen molecules July 4th, 2015

New Biosensor Produced in Iran to Detect Effective Drugs in Cancer Treatment July 4th, 2015

Clues to inner atomic life from subtle light-emission shifts: Hyperfine structure of light absorption by short-lived cadmium atom isotopes reveals characteristics of the nucleus that matter for high precision detection methods July 3rd, 2015

Groundbreaking research to help control liquids at micro and nano scales July 3rd, 2015

Announcements

A 'movie' of ultrafast rotating molecules at a hundred billion per second: A quantum wave-like nature was successfully observed in rotating nitrogen molecules July 4th, 2015

New Biosensor Produced in Iran to Detect Effective Drugs in Cancer Treatment July 4th, 2015

Clues to inner atomic life from subtle light-emission shifts: Hyperfine structure of light absorption by short-lived cadmium atom isotopes reveals characteristics of the nucleus that matter for high precision detection methods July 3rd, 2015

Pioneering Southampton scientist awarded prestigious physics medal July 3rd, 2015

Quantum nanoscience

A 'movie' of ultrafast rotating molecules at a hundred billion per second: A quantum wave-like nature was successfully observed in rotating nitrogen molecules July 4th, 2015

Freezing single atoms to absolute zero with microwaves brings quantum technology closer: Atoms frozen to absolute zero using microwaves July 2nd, 2015

The quantum spin Hall effect is a fundamental property of light June 25th, 2015

Lancaster University revolutionary quantum technology research receives funding boost June 22nd, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project