Highlights
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New widgets and extensions expand the OSSCAR platform for educational notebooks in materials science
In a new article published in Computer Physics Communications, the team of the Open Software Services for Classrooms and Research project (OSSCAR) describes how to create custom custom widgets and extensions that can be used in interactive notebooks to teach computational materials science. The article also introduces two new entries in OSSCAR: a widget to display an interactive periodic table that allows users to group elements into different states, and one to plot and visualize electronic band structures and density of states.
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In search of the perfect materials for fusion reactors
Can theory and computation methods help the search for the best divertor material and thus contribute to making fusion a reality? Scientists in Nicola Marzari’s MARVEL laboratory at EPFL decided to answer the question, and in a new article they present a method for a large-scale screening of potential materials to be used in a nuclear fusion divertor, a component that has to withstand extreme heat and a bombardment of particles. The shortlist of the most promising materials contains tungsten, that has been chosen for the ITER reactor, together with other options that may be considered for future reactors.
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Orbitronics: new material property advances energy-efficient tech
Orbital angular momentum monopoles have been the subject of great theoretical interest as they offer major practical advantages for the emerging field of orbitronics, a potential energy-efficient alternative to traditional electronics. Now, through a combination of robust theory and experiments at the Swiss Light Source SLS at Paul Scherrer Institute PSI, their existence has been demonstrated. The discovery is published in the journal Nature Physics.
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A new benchmark to recognize the hardest problems in materials science
A large collaboration led by MARVEL's Giuseppe Carleo has introduced a method to compare the performance of different algorithms, both classical and quantum ones, when simulating complex phenomena in condensed matter physics. The new benchmark, called V-score, is described in an article just published in Science and has been validated on several examples of quantum many-body problems, pointing to the ones where future quantum computing algorithms may really make a difference.
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The story of Jacutingaite: how a wonder material went from the mine to theory, crystal growth and experiments
The first article of a series about MARVEL's success stories from its 10 years of research. In this story, we revisit how a close collaboration between theorists and experimentalists led to identify, synthesize and test a unique exotic material that until then had only appeared in some samples from a Brazilian mine. The material, called jacutingaite and with the composition Pt2HgSe3, was eventually confirmed to be the first ever material showing the so-called Kane-Mele physics, a quantum phenomenon that had been predicted but never seen in action before. Research is still ongoing on the original jacutingaite and on other materials of its family, and could lead to several technological applications.
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Computational marathon matches the efficiency of the AiiDA platform with the power of Switzerland Alps supercomputer
A group of MARVEL researchers from the Paul Scherrer Institute has conducted a "hero run" on the new Swiss supercomputer, occupying it entirely for about 20 hours with calculations managed remotely by the AiiDA software tools. The run demonstrated the efficiency and stability of AiiDA, that could seamlessly fill the entire capacity of an exascale machine, as well as the performance of the Alps supercomputer, that has been just inaugurated. All the results will soon be published on the Materials Cloud.
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The best of both worlds: combining accurate spectroscopy and thermodynamics for correlated materials
A new mathematical framework developed by MARVEL scientists at EPFL allows to calculate the spectrum of a material and its thermodynamics behavior at the same time, including the total energy and the band structure, and it does this even for complex, correlated materials. The method, published in an article in Physical Review Research, combines thermodynamics from DFT+U and spectra from GW, and was validated on transition metal oxides.
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A paradigm shift in calculating the spectral properties of semiconductors
In a new article just published in Physical Review Research, Nicola Colonna from PSI and MARVEL and Antimo Marrazzo from Scuola Internazionale Superiore di Studi Avanzati (International School of Advanced Studies) in Trieste, Italy, introduce a new approach that allows calculating band structures of semiconductors in a simple way and at low computational cost, even in presence of spin-orbit coupling or complex magnetic configurations. The new method was validated on some well-studied materials and the results of the calculations proved in very good agreements with other well-established but more costly and unwieldy theories, such as many-body perturbation theory, and with experiments. This development will allow efficient and accurate computational screenings of materials databases and enable simulating complex materials under more realistic conditions, such as in presence of defects or at finite temperature.
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A tool to explore the energy landscape of magnetic materials
A new computational method allows to perform a thorough exploration of the energy landscape of magnetic materials, which often have many possible solutions to the electronic structure problem. It allows to access many different starting points in terms of which orbitals are occupied by the electrons, and uses a global algorithm to search systematically for all possible local minima of the energy in a material. The method, as well as its validation on many magnetic systems, has just been published in npj computational materials by scientists from Nicola Marzari's lab at EPFL.
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A direct probe of the quantum geometry of materials
MARVEL scientists at the University of Fribourg have devised new mathematical techniques and applied them to an experimental method called angle-resolved photoemission spectroscopy (ARPES) to measure the Berry curvature, a particular way by which the laws of quantum mechanics interact with the electronic structure of a material and dictate the possible behavior of its electrons. So far this fundamental quantum geometrical property can only be measured indirectly. The study, published in Science Advances, could pave the way to a better understanding of topological materials.
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International collaboration lays the foundation for future AI for materials
Artificial intelligence (AI) is accelerating the development of new materials. A prerequisite for AI in materials research is large-scale use and exchange of data on materials, which is facilitated by a broad international standard. A major international collaboration including MARVEL and CECAM now presents an extended version of the OPTIMADE standard.
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A chain of copper and carbon atoms may be the thinnest metallic wire
Researchers at EPFL have employed computational tools to look for new 1-D materials that could be exfoliated from known three-dimensional crystals. Out of an initial list of over 780,000 crystals, they came up with a list of 800 1-D materials, out of which they selected the 14 best candidates - compounds that have not been synthesized as actual wires yet, but that simulations suggest as feasible. Among them is the metallic wire CuC2, a straight-line chain composed by two carbon atoms and one copper atom, the thinnest metallic nanowire stable at 0 K found so far. The article is published in ACS Nano.