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
Further Improvement of Qubit Lifetime for Quantum Computers
09.12.2016 | Forschungszentrum Jülich
Electron highway inside crystal
09.12.2016 | Julius-Maximilians-Universität Würzburg
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine