The goal is topological insulators (TI), man-made crystals that are able to conduct electrical current on their surfaces, while acting as insulators throughout the interior of the crystal. Discovering TIs has become of great interest to scientists, but because of the lack of a rational blueprint for creating them, researchers have had to rely on trial-and-error approaches, with limited success to date.
Because of their unique properties, TIs can be created that conduct electricity more efficiently while also being much smaller that conventional wires or devices. They are ideal candidates to become quantum electronics devices, the Duke researchers said.
The "key" developed by the Duke investigators is a mathematical formulation that unlocks the data stored in a database of potential TI ingredients. It provides specific recipes for searching for TIs with the desired properties.
In November, Stefano Curtarolo, professor of mechanical engineering and materials sciences and physics at Duke's Pratt School of Engineering and founder of the Duke's Center for Materials Genomics, and colleagues reported the establishment of a materials genome repository (aflowlib.org) which allows scientists to stop using trial-and-error methods in the search for efficient alloys.
The project developed by the Duke engineers covers thousands of compounds, and provides detailed recipes for creating the most efficient combinations for a particular purpose, much like hardware stores mix different colors of paint to achieve the desired result. The project is the keystone of the newly formed Duke's Center for Materials Genomics.
"While extremely helpful and important, a database is intrinsically a sterile repository of information, without a soul and without life. We need to find the materials' 'genes,'" said Curtarolo. "We have developed what we call the 'topological descriptor,' that when applied to the database can provide the directions for producing crystals with desired properties."
While developing the key to this database, the team also discovered a new class of systems that could not have been anticipated without such a "genetic" approach.
The Duke research was reported online in the journal Nature Materials. The work was supported by the Office of Navy Research and the National Science Foundation.
The new descriptor developed by the Duke team basically can determine status of any specific combination of element under investigation. On one end of the spectrum, Curtarolo explained, is "fragile."
"We can rule those combinations out because, what good is a new type of crystal if it would be too difficult to grow, or if grown, would not likely survive?" Curtarolo said. A second group of combinations would be a middle group termed "feasible."
But what excites Curtarolo most are those combinations found to be "robust." These crystals are stable and can be easily and efficiently produced. Just as importantly, these crystals can be grown in different directions,which gives them the advantage of tailored electrical properties by simple growth processes.
While TIs are currently in the experimental stage, Curtarolo believes that with this new tool, scientists should have a powerful framework for engineering a wide variety of them.
Kesong Yang, a post-doctoral fellow in Curtarolo's laboratory, is first author of the paper. Other members of the team were Duke's Shidong Wang, Wahyu Setyawan, Pacific Northwest Laboratory and Marco Buongiorno Nardelli, University of North Texas and the Oak Ridge National Laboratory.
Citation: "A Search Model for Topological Insulators with High-Throughput Robustness Descriptors," Kesong Yang, et. al., Nature Materials [DOI: 10.1038/NMAT3332].
Richard Merritt | EurekAlert!
Melting solid below the freezing point
23.01.2017 | Carnegie Institution for Science
An innovative high-performance material: biofibers made from green lacewing silk
20.01.2017 | Fraunhofer-Institut für Angewandte Polymerforschung IAP
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...
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...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
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...
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...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
23.01.2017 | Health and Medicine
23.01.2017 | Physics and Astronomy
23.01.2017 | Process Engineering