Why is this important? Understanding supersolid helium brings us closer to understanding its close cousins superconductivity and superfluidity.
Physicists had long thought that the unusual behavior of torsion oscillators containing solid helium meant that chilling helium down to temperatures near absolute zero prompts its transformation into a supersolid. It is certainly solid, but in this physical quest, there was a nagging question: Is it a true supersolid?
To gain new perspectives on solid helium, new research tools were needed. “Think of this analogy: when Galileo first peered through a telescope, he saw ears on Saturn. With improved technology, humanity began to understand those ears were actually rings around the planet. And with better technology, we saw the differences in the rings. To further understand solid helium, science had to invent new approaches,” says Séamus Davis, Cornell professor of physics. “Helium is a pure material. We’re gaining a new understanding of the fundamental issues of how nature works, of how the universe works.”
In fact, in this paper, the researchers show instead a more prosaic explanation: There are moving defects in the solid helium crystals, and their relaxation time falls with rising temperatures. This is more consistent with the torsional oscillation (shaking) experiments conducted at Cornell.
The researchers learned that the unusual properties of solid helium do not reflect a clunky transition between the solid state and a supersolid state. It behaves like a dimmer switch and presents a smooth transition near absolute zero.
The research, “Interplay of Rotational, Relaxational, and Shear Dynamics in Solid 4He,” is reported in Science (May 13, 2011). The lead authors are Ethan Pratt, Cornell Ph.D. ’10, post-doctoral researcher at Cornell and Ben Hunt, Cornell Ph.D. ’09, currently at Massachusetts Institute of Technology. The other authors are Séamus Davis, the J.G. White Distinguished Professor in the Physical Sciences at Cornell, and graduate student Vikram Gadagkar; Alexander Balatsky and Matthias Graf, Los Alamos National Laboratory; and Minoru Yamashita at Kyoto University.
Funding for this research: the National Science Foundation and the Kavli Institute for Theoretical Physics. Research at Los Alamos was supported by U.S. Department of Energy, through the Laboratory Directed Research and Development program.
Blaine Friedlander | Newswise Science News
NASA laser communications to provide Orion faster connections
30.03.2017 | NASA/Goddard Space Flight Center
Pinball at the atomic level
30.03.2017 | Max-Planck-Institut für Struktur und Dynamik der Materie
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
30.03.2017 | Health and Medicine
30.03.2017 | Health and Medicine
30.03.2017 | Medical Engineering