Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Insights into the World of Quantum Materials

19.09.2014

In Innsbruck, Austria, a team of physicists led by Francesca Ferlaino experimentally observed how the anisotropic properties of particles deform the Fermi surface in a quantum gas. The work published in Science provides the basis for future studies on how the geometry of particle interactions may influence the properties of a quantum system.

How a system behaves is determined by its interaction properties. An important concept in condensed matter physics for describing the energy distribution of electrons in solids is the Fermi surface, named for Italian physicist Enrico Fermi. The existence of the Fermi surface is a direct consequence of the Pauli exclusion principle, which forbids two identical fermions from occupying the same quantum state simultaneously.


The Erbium Team (from left): Kiyotaka Aikawa, Albert Frisch, Simon Baier, Michael Mark, and Francesca Ferlaino (not pictured: Cornelis Ravensbergen)

University of Innsbruck

Energetically, the Fermi surface divides filled energy levels from the empty ones. For electrons and other fermionic particles with isotropic interactions – identical properties in all directions - the Fermi surface is spherical. “This is the normal case in nature and the basis for many physical phenomena,” says Francesca Ferlaino from the Institute for Experimental Physics at the University of Innsbruck.

“When the particle interaction is anisotropic – meaning directionally dependent – the physical behavior of a system is completely altered. Introducing anisotropic interactions can deform the Fermi surface and it is predicted to assume an ellipsoidal shape.” The deformation of the Fermi surface is caused by the interplay between strong magnetic interaction and the Pauli exclusion principle. Francesca Ferlaino and her experimental research group have now been able to show such a deformation for the first time.

Simulation in ultracold quantum gas

For their experiment, the quantum physicists confined a gas of fermionic erbium atoms in a laser trap and cooled it to almost absolute zero. The element erbium is strongly magnetic, which causes extreme dipolar behavior. The interaction between these atoms is, therefore, directionally dependent. When the physicists release the ultracold gas from the trap, they are able to infer the shape of the Fermi surface from the momentum distribution of the particles.

“Erbium atoms behave similarly to magnets, which means that their interaction is strongly dependent on the direction in which the particles interact. Our experiment shows that the shape of the Fermi surface depends on the geometry of the interaction and is not spherical anymore,” explains first author of the study Kiyotaka Aikawa the phenomenon that is extremely difficult to observe

Basic question

“The general question we deal with here is how the geometry of particle interactions influences the quantum properties of matter,” explains Francesca Ferlaino. Answering this question is of interest for physicists from different branches of physics such as the study of high-temperature superconductors. “We need a better understanding of these properties to develop new quantum systems,” underlines Francesca Ferlaino. Ultracold quantum gases once more provide an ideal platform for simulating complex scenarios.

This work was financially supported by the Austrian Ministry of Science, the Austrian Science Fund and the European Union. Since July 2014 ERC and START awardee Francesca Ferlaino is Scientific Director at the Institute for Quantum Optics and Quantum Information (IQOQI) of the Austrian Academy of Sciences.

Publication: Observation of Fermi surface deformation in a dipolar quantum gas. K. Aikawa,
S. Baier, A. Frisch, M. Mark, C. Ravensbergen, F. Ferlaino. Science 2014
DOI: 10.1126/science.1255259 arXiv:1405.2154 http://arxiv.org/abs/1405.2154

Contact:
Univ.-Prof. Dr. Francesca Ferlaino
Institute for Experimental Physics
University of Innsbruck
Institute for Quantum Optics and Quantum Information
Austrian Academy of Sciences
6020 Innsbruck, Austria
Phone: +43 512 507-52440 (Lab.: -52441), (Secr.: -52449), (Fax: -2921)
Email: francesca.ferlaino@uibk.ac.at
Web: http://www.ultracold.at

Christian Flatz
Public Relations office
University of Innsbruck
Phone: +43 512 507 32022
Email: christian.flatz@uibk.ac.at
Web: http://www.uibk.ac.at

Weitere Informationen:

http://dx.doi.org/10.1126/science.1255259 - Observation of Fermi surface deformation in a dipolar quantum gas. K. Aikawa, S. Baier, A. Frisch, M. Mark, C. Ravensbergen, F. Ferlaino. Science 2014
http://www.ultracold.at - Ultracold Atoms and Quantum Gases

Dr. Christian Flatz | Universität Innsbruck

Further reports about: Electrons Experimental Physics Fermi Innsbruck QUANTUM interactions trap

More articles from Physics and Astronomy:

nachricht MEMS chips get metatlenses
21.02.2018 | American Institute of Physics

nachricht International team publishes roadmap to enhance radioresistance for space colonization
21.02.2018 | Biogerontology Research Foundation

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Researchers invent tiny, light-powered wires to modulate brain's electrical signals

21.02.2018 | Life Sciences

The “Holy Grail” of peptide chemistry: Making peptide active agents available orally

21.02.2018 | Life Sciences

Atomic structure of ultrasound material not what anyone expected

21.02.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>