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Primeur weekly 2018-01-22

Focus

European Commission explains why Joint Undertaking is well suited as legal instrument to help create EuroHPC ecosystem ...

Exascale supercomputing

Exascale architectures lead to greener and more advanced combustion systems ...

Call for Proposals: Aurora Early Science Programme expands to include data and learning projects ...

Quantum computing

HKU quantum physicist Dr. Giulio Chiribella receives Croucher Senior Research Fellowship 2018 ...

New input for quantum simulations ...

Focus on Europe

Eni boots up HPC4 and makes its computing system the world's most powerful in the industry ...

ONERA to install new supercomputer for aerospace research ...

Atos to deliver the most powerful supercomputer in Germany at Forschungszentrum Jülich ...

Hardware

Cray announces selected preliminary 2017 financial results ...

India's Ministry of Earth Sciences deploys new Cray XC40 supercomputers and Cray storage systems ...

University of Virginia Engineering tapped to lead $27.5 million centre to reinvent computing ...

Asperitas creates AsperitasEI business unit to bring circular energy and data centre projects to life ...

CSRA selects edge solutions and Supermicro computer for expansion, increasing NASA computing capacity to 5 petaFLOPS ...

Mellanox ConnectX-5 Ethernet adapter wins Linley Group Analyst Choice Award for Best Networking Chip ...

Notre Dame to lead $26 million multi-university research centre developing next-generation computing technologies ...

New $32 million centre at University of Michigan reimagines how computers are designed ...

New C-BRIC centre will tackle brain-inspired computing ...

Ultra-thin memory storage device paves way for more powerful computing ...

Applications

US DOE announces funding for new HPC4Manufacturing industry projects ...

NOAA kicks off 2018 with massive supercomputer upgrade ...

UMass Center for Data Science partners with Chan Zuckerberg Initiative to accelerate science and medicine ...

Himawari-8 data assimilated simulation enables 10-minute updates of rain and flood predictions ...

Ohio Supercomputer Center to host free webinar on innovative web-based HPC portal ...

2D tin (stanene) without buckling: A possible topological insulator ...

Uncovering decades of questionable investments ...

Groundbreaking conference examines how AI transforms our world ...

Framework for Research Data Management makes life simpler for researchers ...

The Cloud

New centre headquartered at Carnegie Mellon will build smarter networks to connect edge devices to the Cloud ...

IBM and Salesforce strengthen strategic partnership ...

ANSYS and Rescale offer on-demand, pay-per-use ANSYS software on Rescale's ScaleX Cloud HPC platform ...

2D tin (stanene) without buckling: A possible topological insulator

High-resolution STM image of stanene prepared on a Ag2Sn surface alloy. The honeycomb stanene structure model is superimposed. Credit: Junji Yuhara.19 Jan 2018 Nagoya - Nagoya University-led researchers have produced 2D sheets of tin atoms predicted to have exotic uses in electronics. Sometimes it pays to be two-dimensional. The merits of graphene, a 2D sheet of carbon atoms, are well established. In its wake have followed a host of "post-graphene materials" - structural analogues of graphene made of other elements like silicon or germanium.

Now, an international research team led by Nagoya University in Japan, involving Aix-Marseille University in France, the Max Planck Institute in Hamburg, Germany, and the University of the Basque country in Spain, has unveiled the first truly planar sample of stanene: single sheets of tin (Sn) atoms. Planar stanene is hotly tipped as an extraordinary electrical conductor for high technology.

Just as graphene differs from ordinary graphite, so does stanene behave very differently to humble tin in bulk form. Because of relatively strong spin-orbit interactions for electrons in heavy elements, single-layer tin is predicted to be a "topological insulator", also known as a quantum spin Hall (QSH) insulator. Materials in this remarkable class are electrically insulating in their interiors, but have highly conductive surfaces/edges. This, in theory, makes a single-layered topological insulator an ideal wiring material for nano-electronics. Moreover, the highly conductive channels at the edge of these materials can carry special chiral currents with spins locked with transport directions, which makes them also very appealing for spintronics applications.

In previous studies, where stanene was grown on substrates of bismuth telluride or antimony, the tin layers turned out to be highly buckled and relatively inhomogeneous. The Nagoya team instead chose silver (Ag) as their host - specifically, the Ag(111) crystal facet, whose lattice constant is slightly larger than that of the freestanding stanene, leading to the formation of flattened tin monolayer in a large area, one step closer to the scalable industrial applications.

Individual tin atoms were slowly deposited onto silver, known as epitaxial growth. Crucially, the stanene layer did not form directly on top of the silver surface. Instead, as shown by core-level spectroscopy, the first step was the formation of a surface alloy (Ag2Sn) between the two species. Then, another round of tin deposition produced a layer of pure, highly crystalline stanene atop the alloy. Tunneling microscopy shows striking images of a honeycomb lattice of tin atoms, illustrating the hexagonal structure of stanene.

The alloy guaranteed the flatness of the tin layer, as confirmed by density-functional theory calculations. Junji Yuhara, lead author of an article by the team published in2D Materials, explained: "Stanene follows the crystalline periodicity of the Ag2Sn surface alloy. Therefore, instead of buckling as it would in isolation, the stanene layer flattens out - at the cost of a slight strain - to maximize contact with the alloy beneath." This mutual stabilization between stanene and host not only keeps the stanene layers impeccably flat, but lets them grow to impressive sizes of around 5,000 square nanometers.

Planar stanene has exciting prospects in electronics and computing. "The QSH effect is rather delicate, and most topological insulators only show it at low temperatures", according to project team leader Guy Le Lay at Aix-Marseille University. "However, stanene is predicted to adopt a QSH state even at room temperature and above, especially when functionalized with other elements. In the future, we hope to see stanene partnered up with silicene in computer circuitry. That combination could drastically speed up computational efficiency, even compared with the current cutting-edge technology."

The article, " Large area planar stanene epitaxially grown on Ag(111) ", was published in2D Materials.

Source: Nagoya University

Back to Table of contents

Primeur weekly 2018-01-22

Focus

European Commission explains why Joint Undertaking is well suited as legal instrument to help create EuroHPC ecosystem ...

Exascale supercomputing

Exascale architectures lead to greener and more advanced combustion systems ...

Call for Proposals: Aurora Early Science Programme expands to include data and learning projects ...

Quantum computing

HKU quantum physicist Dr. Giulio Chiribella receives Croucher Senior Research Fellowship 2018 ...

New input for quantum simulations ...

Focus on Europe

Eni boots up HPC4 and makes its computing system the world's most powerful in the industry ...

ONERA to install new supercomputer for aerospace research ...

Atos to deliver the most powerful supercomputer in Germany at Forschungszentrum Jülich ...

Hardware

Cray announces selected preliminary 2017 financial results ...

India's Ministry of Earth Sciences deploys new Cray XC40 supercomputers and Cray storage systems ...

University of Virginia Engineering tapped to lead $27.5 million centre to reinvent computing ...

Asperitas creates AsperitasEI business unit to bring circular energy and data centre projects to life ...

CSRA selects edge solutions and Supermicro computer for expansion, increasing NASA computing capacity to 5 petaFLOPS ...

Mellanox ConnectX-5 Ethernet adapter wins Linley Group Analyst Choice Award for Best Networking Chip ...

Notre Dame to lead $26 million multi-university research centre developing next-generation computing technologies ...

New $32 million centre at University of Michigan reimagines how computers are designed ...

New C-BRIC centre will tackle brain-inspired computing ...

Ultra-thin memory storage device paves way for more powerful computing ...

Applications

US DOE announces funding for new HPC4Manufacturing industry projects ...

NOAA kicks off 2018 with massive supercomputer upgrade ...

UMass Center for Data Science partners with Chan Zuckerberg Initiative to accelerate science and medicine ...

Himawari-8 data assimilated simulation enables 10-minute updates of rain and flood predictions ...

Ohio Supercomputer Center to host free webinar on innovative web-based HPC portal ...

2D tin (stanene) without buckling: A possible topological insulator ...

Uncovering decades of questionable investments ...

Groundbreaking conference examines how AI transforms our world ...

Framework for Research Data Management makes life simpler for researchers ...

The Cloud

New centre headquartered at Carnegie Mellon will build smarter networks to connect edge devices to the Cloud ...

IBM and Salesforce strengthen strategic partnership ...

ANSYS and Rescale offer on-demand, pay-per-use ANSYS software on Rescale's ScaleX Cloud HPC platform ...