Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Quantum hall effect observed at room temperature

19.02.2007
Using the highest magnetic fields in the world, an international team of researchers has observed the quantum Hall effect – a much studied phenomenon of the quantum world – at room temperature.

The quantum Hall effect was previously believed to only be observable at temperatures close to absolute zero (equal to minus 459 degrees). But when scientists at the National High Magnetic Field Laboratory in the U.S. and at the High Field Magnet Laboratory in the Netherlands put a recently developed new form of carbon called graphene in very high magnetic fields, scientists were surprised by what they saw.

"At room temperature, these electron waves are usually destroyed by the jiggling atoms and the quantum effects are destroyed," said Nobel Prize winner Horst Stormer, physics professor at Columbia University and one of the paper's authors. "Only on rare occasions does this shimmering quantum world survive to the temperature scale of us humans."

The quantum Hall effect is the basis for the international electrical resistance standard used to characterize even everyday materials that conduct electricity, such as the copper wires in a home. It was first discovered in 1980 by the German physicist Klaus von Klitzing, who was awarded a Nobel Prize in 1985 for his discovery. Until recently the quantum Hall effect was considered to belong to the realm of very low temperatures.

That opinion began to change, however, with the ability to create very high magnetic fields and with the discovery of graphene, a single atomic sheet of atoms about as strong as diamond. Together, these two things have allowed scientists to push this fragile quantum effect all the way to room temperature. Now there is a way to see curious and often surprising quantum effects, such as frictionless current flow and resistances as accurate as a few parts per billion, even at room temperature.

The research was carried out by scientists from the University of Manchester in England, Columbia University in New York, the National High Magnetic Field Laboratory in Tallahassee, Florida, the High Field Magnet Laboratory in Nijmegen, Netherlands, and the Foundation for Fundamental Research on Matter, also in the Netherlands. Their article appears in Science Express, the advanced online publication of Science magazine, a top American journal with international stature.

The scientists believe that these findings may one day lead to a compact resistance standard working at elevated temperatures and magnetic fields that are easily attainable at the National High Magnetic Field Laboratory.

"The more we understand the strange world of quantum physics, the better we can design the next generation of ultra-small electrical devices, which already are pushing into the quantum regime," said Gregory S. Boebinger, director of the U.S. magnet lab.

"This is a really amazing discovery for a quantum Hall physicist," said Uli Zeitler, senior scientist at the High Field Magnet Laboratory. "For more than two decades, we've focused our research on exploring new frontiers such as very low temperatures and extremely sophisticated materials, and now it appears that we can just measure a quantum Hall effect in a pencil-trace and at room temperature."

The room temperature quantum Hall effect was discovered independently in the two high field labs, in the 45-tesla Hybrid magnet in Tallahassee and in a 33-tesla resistive magnet in Nijmegen. Both research groups agreed that a common announcement on both sides of the Atlantic was the right thing to do.

"Because so many scientists are exploring this exciting new material, we are all on this roller coaster together," said Boebinger. "Sometimes it makes sense to put competitiveness aside and write a better paper together."

Susan Ray | EurekAlert!
Further information:
http://www.magnet.fsu.edu

More articles from Physics and Astronomy:

nachricht Tune your radio: galaxies sing while forming stars
21.02.2017 | Max-Planck-Institut für Radioastronomie

nachricht Breakthrough with a chain of gold atoms
17.02.2017 | Universität Konstanz

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Impacts of mass coral die-off on Indian Ocean reefs revealed

21.02.2017 | Earth Sciences

Novel breast tomosynthesis technique reduces screening recall rate

21.02.2017 | Medical Engineering

Use your Voice – and Smart Homes will “LISTEN”

21.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>