In a standard scanning tunneling microscope image, left, the atoms in a cuprate crystal the bright blobs) are not in a particularly orderly arrangement. But an image of the probable distribution of electrons, right, shows that clouds of them have arranged themselves in what amounts to an electronic crystal. The brighter areas seem to contain more electrons, but the reason for this is unknown.
To protect the instrument from outside vibrations, the modified STM at Cornell is enclosed in a sealed, isolated room mounted on massive supports. Copyright © Cornell University
With equipment so sensitive that it can locate clusters of electrons, Cornell University and University of Tokyo physicists have -- sort of -- explained puzzling behavior in a much-studied high-temperature superconductor, perhaps leading to a better understanding of how such superconductors work.
It turns out that under certain conditions the electrons in the material pretty much ignore the atoms to which they are supposed to be attached, arranging themselves into a neat pattern that looks like a crystal lattice. The behavior occurs in a phase physicists have called a "pseudogap," but because the newly discovered arrangement looks like a checkerboard in scanning tunneling microscope (STM) images, J.C. Séamus Davis, Cornell professor of physics, calls the phenomenon a "checkerboard phase."
Davis, Hidenori Takagi, professor of physics at the University of Tokyo, and co-workers describe the observations in the Aug. 26, 2004, issue of the journal Nature. An article about the work also is scheduled to appear in the September issue of Physics Today.
Bill Steele | EurekAlert!
Significantly more productivity in USP lasers
06.12.2016 | Fraunhofer-Institut für Lasertechnik ILT
Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore
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...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
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