Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A crack in the case for supersolids

22.06.2010
Reports of supersolid helium may have been premature

New experiments are casting doubt on previously reported observations of supersolid helium. In a paper appearing in the current issue of Physical Review Letters (PRL), John Reppy (Cornell University) presents research suggesting that prior experiments that seemed to show signs of supersolidity were in fact the result of the plastic deformation of normal helium.

Physicists have long known that helium can become a superfluid at low temperatures, allowing it to flow completely friction free, spontaneously climb walls, and exhibit other counterintuitive characteristics. Based on quantum mechanical calculations dating back to the 1970's, some physicists predicted similar effects in solid materials. In particular, they expected ultracold solid helium could become a mixture of normal solid and supersolid forms.

It wasn't until 2004 that physicists were able to devise a way to look for supersolid behavior in helium. They filled a hollow torsion pendulum (a type of pendulum that rotates rather than swinging back and forth) with helium, then measured the rate that it twisted as the helium was cooled. Because the periodic twisting rate depends in part on the amount of normal helium in the pendulum cavity, they expected that the period would change if some of the helium became supersolid. When researchers found the period change they were expecting, many physicists declared the hunt for supersolid helium had finally come to an end.

According to Reppy's experiments, which are the subject of a Viewpoint by John Beamish (University of Alberta) in the latest edition of APS Physics (http://physics.aps.org), the period change may have had nothing to do with supersolids at all. Instead, it's possible that the normal helium was deforming as the pendulum twisted. The conclusion is the result of a new pendulum design and methods to control the structure of the solid helium inside, which should allow physicists to tease out the effects of supersolid helium from the effects of deformations.

It's not yet clear that observations of supersolid helium were in error. Even if that's the case, the possibility that deformations are responsible for the period change in a helium-filled pendulum is nearly as intriguing to physicists as supersolid helium because it may result from a poorly understood phenomenon known as quantum plasticity. Only further research will determine whether supersolidity or quantum plasticity is responsible for the odd behavior of super-cold, solid helium.

About APS Physics:

APS Physics (http://physics.aps.org) publishes expert written commentaries and highlights of papers appearing in the journals of the American Physical Society.

James Riordon | EurekAlert!
Further information:
http://physics.aps.org
http://www.aps.org

More articles from Physics and Astronomy:

nachricht PPPL physicist uncovers clues to mechanism behind magnetic reconnection
24.01.2017 | DOE/Princeton Plasma Physics Laboratory

nachricht Electrocatalysis can advance green transition
23.01.2017 | Technical University of Denmark

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: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Arctic melt ponds form when meltwater clogs ice pores

24.01.2017 | Earth Sciences

Synthetic nanoparticles achieve the complexity of protein molecules

24.01.2017 | Life Sciences

PPPL physicist uncovers clues to mechanism behind magnetic reconnection

24.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>