By modifying a familiar tool in nanoscience – the Scanning Tunneling Microscope – a team at Cornell University’s Laboratory for Atomic and Solid State Physics have been able to visualize what happens when they change the electronic structure of a “heavy fermion” compound made of uranium, ruthenium and silicon. What they found sheds light on superconductivity – the movement of electrons without resistance – which typically occurs at extremely low temperatures and that researchers hope one day to achieve at something close to room temperature, which would revolutionize electronics.
What they found was that, while at higher-temperatures magnetism is detrimental to superconductivity, at low temperatures in heavy fermion materials, magnetic atoms are a necessity. “We found that removing the magnetic atoms proved detrimental to the flow [of electrons],” said researcher Mohammad Hamidian. This is important, Hamidian explains, because “if we can resolve how superconductivity can co-exist with magnetism, then we have a whole new understanding of superconductivity, which could be applied toward creating high-temperature superconductors. In fact, magnetism at the atomic scale could become a new tuning parameter of how you can change the behavior of new superconducting materials that we make.”
To make things finding, the researchers modified a scanning microscope that lets you pull or push electrons into a material. With the modification, the microscope could also measure how hard it was to push and pull – a development that Hamidian explains is also significant. “By doing this, we actually learn a lot about the material’s electronic structure. Then by mapping that structure out over a wide area, we can start seeing variations in those electronic states, which come about for quantum-mechanical reasons. Our newest advance, crucial to this paper, was the ability to see at each atom the strength of the interactions that make the electrons ‘heavy.'”
The Cornell experiment and its results are presented this week by the Proceedings of the National Academy of Sciences (See PNAS, available online at www.pnas.org). The research team included J.C. Séamus Davis, a member of the Kavli Institute at Cornell for Nanoscale Science and developer of the SI-STM technique. Working with synthesized samples created by Graeme Luke from McMaster University (Canada), the experiment was designed by Hamidian, a post-doctoral fellow in Davis’ research group, along with Andrew R. Schmidt, a former student of Davis at Cornell and now a post-doctoral fellow in physics at UC Berkeley.
For the complete interview with Hamidian, visit: http://www.kavlifoundation.org/science-spotlights/Cornell-disturbing-nanosphere-superconductivity
James Cohen | Newswise Science News
A new force for optical tweezers awakens
19.06.2019 | University of Gothenburg
View of the Earth in front of the Sun
19.06.2019 | Georg-August-Universität Göttingen
The quality of additively manufactured components depends not only on the manufacturing process, but also on the inline process control. The process control ensures a reliable coating process because it detects deviations from the target geometry immediately. At LASER World of PHOTONICS 2019, the Fraunhofer Institute for Laser Technology ILT will be demonstrating how well bi-directional sensor technology can already be used for Laser Material Deposition (LMD) in combination with commercial optics at booth A2.431.
Fraunhofer ILT has been developing optical sensor technology specifically for production measurement technology for around 10 years. In particular, its »bd-1«...
The well-known representation of chemical elements is just one example of how objects can be arranged and classified
The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to...
Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.
Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...
Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.
The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...
Discovery by Brazilian and US researchers could change the classification of two species, which appear more akin to jellyfish than was thought.
The tube anemone Isarachnanthus nocturnus is only 15 cm long but has the largest mitochondrial genome of any animal sequenced to date, with 80,923 base pairs....
29.04.2019 | Event News
17.04.2019 | Event News
15.04.2019 | Event News
19.06.2019 | Physics and Astronomy
19.06.2019 | Information Technology
19.06.2019 | Materials Sciences