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Primeur weekly 2020-09-14

Focus

Some RISC-V high performance implementations presented at RISC-V Global Forum by European Processor Initiative, NSITEXE, OpenBLAS, and SemiDynamics ...

Exascale supercomputing

Combustion pioneer named Department of Energy fellow ...

Quantum computing

New method prevents quantum computers from crashing ...

Q-CTRL and Quantum Machines announce partnership to accelerate quantum computing development ...

Cambridge Quantum Computing welcomes Mehdi Bozzo-Rey ...

Focus on Europe

Researchers develop molecule to store solar energy ...

First release of PROCESS software now available ...

From artificial intelligence to nanomaterials and astrophysics - Seven Irish research projects to benefit from EuroHPC Academic Flagship Programme ...

Middleware

SDSC to help create science gateway for new materials discovery ...

Hardware

NCSA's Donna J. Cox honoured with rare IPS Technology Innovation Award ...

Advanced NVMe controller technology for next generation memory devices ...

Credo announces the DOVE platform, its second generation of low power PAM4 DSPs for 100G/200G/400G data networks ...

Tachyum opens U.S., EU and NATO Government Business Unit ...

National Science Foundation awards CENIC an international networking grant for operation of Pacific Wave ...

UCF Consortium receives open source contribution from Arm to speed access to persistent memory storage ...

Liqid announces agreement with Arrow Electronics to bring composable disaggregated infrastructure solutions to data centres worldwide ...

Research and Markets to issue Global Hybrid Memory Cube (HMC) and High-Bandwidth Memory (HBM) Suppliers Strategic Positioning and Leadership Quadrant Report 2020 ...

Genomics England scales up genomic sequencing with Quantum ActiveScale object storage ...

NVIDIA to acquire Arm for $40 billion, creating world's premier computing company for the age of AI ...

Applications

NCSA and University of Illinois announce new Center for AstroPhysical Surveys ...

Lead lab selected for next-generation cosmic microwave background experiment ...

Insilico announces the launch of AI-powered COVIDomic to support COVID-19 research worldwide ...

Model shows that the speed neurons fire impacts their ability to synchronize ...

Physicists achieve tunable spin wave excitation ...

EBRAINS makes bid to enter the European Research Infrastructure Roadmap with ten-country strong coalition and France as lead country ...

Mysterious cellular droplets come into focus ...

The presence of resonating cavities above sunspots has been confirmed ...

The Hospital Clínic and BSC will use artificial intelligence to predict the evolution of patients with COVID-19 ...

ORIGINS - answers to existential questions ...

Altair announces 2020 Global Technology Conference to explore "The Future of..." ...

The Cloud

National Science Foundation-funded CloudBank now operational ...

Schlumberger, IBM and Red Hat announce major hybrid Cloud collaboration for the energy industry ...

Red Hat Marketplace aims to accelerate open hybrid Cloud innovation with certified software solutions ready to run on any Cloud ...

Renesas introduces DDR5 data buffer for high-performance server and Cloud service applications ...

NETINT deploys video transcoding technology in the Nimbix Cloud ...

Physicists achieve tunable spin wave excitation


Magnon excitation. Credit: Daria Sokol/MIPT Press Office.
8 Sep 2020 Moscow - Physicists from the Moscow Institute of Physics and Technology (MIPT) and the Russian Quantum Center, joined by colleagues from Saratov State University and Michigan Technological University, have demonstrated new methods for controlling spin waves in nanostructured bismuth iron garnet films via short laser pulses. Presented inNano Letters, the solution has potential for applications in energy-efficient information transfer and spin-based quantum computing.

A particle's spin is its intrinsic angular momentum, which always has a direction. In magnetized materials, the spins all point in one direction. A local disruption of this magnetic order is accompanied by the propagation of spin waves, whose quanta are known as magnons.

Unlike the electrical current, spin wave propagation does not involve a transfer of matter. As a result, using magnons rather than electrons to transmit information leads to much smaller thermal losses. Data can be encoded in the phase or amplitude of a spin wave and processed via wave interference or non-linear effects.

Simple logical components based on magnons are already available as sample devices. However, one of the challenges of implementing this new technology is the need to control certain spin wave parameters. In many regards, exciting magnons optically is more convenient than by other means, with one of the advantages presented in the recent paper in Nano Letters .

The researchers excited spin waves in a nanostructured bismuth iron garnet. Even without nanopatterning, that material has unique optomagnetic properties. It is characterized by low magnetic attenuation, allowing magnons to propagate over large distances even at room temperature. It is also highly optically transparent in the near infrared range and has a high Verdet constant.

The film used in the study had an elaborate structure: a smooth lower layer with a one-dimensional grating formed on top, with a 450-nanometer period. This geometry enables the excitation of magnons with a very specific spin distribution, which is not possible for an unmodified film.

To excite magnetization precession, the team used linearly polarized pump laser pulses, whose characteristics affected spin dynamics and the type of spin waves generated. Importantly, wave excitation resulted from optomagnetic rather than thermal effects.

The researchers relied on 250-femtosecond probe pulses to track the state of the sample and extract spin wave characteristics. A probe pulse can be directed to any point on the sample with a desired delay relative to the pump pulse. This yields information about the magnetization dynamics in a given point, which can be processed to determine the spin wave's spectral frequency, type, and other parameters.

Unlike the previously available methods, the new approach enables controlling the generated wave by varying several parameters of the laser pulse that excites it. In addition to that, the geometry of the nanostructured film allows the excitation centre to be localized in a spot about 10 nanometers in size. The nanopattern also makes it possible to generate multiple distinct types of spin waves. The angle of incidence, the wavelength and polarization of the laser pulses enable the resonant excitation of the waveguide modes of the sample, which are determined by the nanostructure characteristics, so the type of spin waves excited can be controlled. It is possible for each of the characteristics associated with optical excitation to be varied independently to produce the desired effect.

"Nanophotonics opens up new possibilities in the area of ultrafast magnetism", stated the study's co-author, Alexander Chernov, who heads the Magnetic Heterostructures and Spintronics Lab at MIPT. "The creation of practical applications will depend on being able to go beyond the submicrometer scale, increasing operation speed and the capacity for multitasking. We have shown a way to overcome these limitations by nanostructuring a magnetic material. We have successfully localized light in a spot few tens of nanometers across and effectively excited standing spin waves of various orders. This type of spin waves enables the devices operating at high frequencies, up to the terahertz range."

The paper experimentally demonstrates an improved launch efficiency and ability to control spin dynamics under optical excitation by short laser pulses in a specially designed nanopatterned film of bismuth iron garnet. It opens up new prospects for magnetic data processing and quantum computing based on coherent spin oscillations.

The study was supported by the Russian Ministry of Science and Higher Education.
Source: Moscow Institute of Physics and Technology - MIPT

Back to Table of contents

Primeur weekly 2020-09-14

Focus

Some RISC-V high performance implementations presented at RISC-V Global Forum by European Processor Initiative, NSITEXE, OpenBLAS, and SemiDynamics ...

Exascale supercomputing

Combustion pioneer named Department of Energy fellow ...

Quantum computing

New method prevents quantum computers from crashing ...

Q-CTRL and Quantum Machines announce partnership to accelerate quantum computing development ...

Cambridge Quantum Computing welcomes Mehdi Bozzo-Rey ...

Focus on Europe

Researchers develop molecule to store solar energy ...

First release of PROCESS software now available ...

From artificial intelligence to nanomaterials and astrophysics - Seven Irish research projects to benefit from EuroHPC Academic Flagship Programme ...

Middleware

SDSC to help create science gateway for new materials discovery ...

Hardware

NCSA's Donna J. Cox honoured with rare IPS Technology Innovation Award ...

Advanced NVMe controller technology for next generation memory devices ...

Credo announces the DOVE platform, its second generation of low power PAM4 DSPs for 100G/200G/400G data networks ...

Tachyum opens U.S., EU and NATO Government Business Unit ...

National Science Foundation awards CENIC an international networking grant for operation of Pacific Wave ...

UCF Consortium receives open source contribution from Arm to speed access to persistent memory storage ...

Liqid announces agreement with Arrow Electronics to bring composable disaggregated infrastructure solutions to data centres worldwide ...

Research and Markets to issue Global Hybrid Memory Cube (HMC) and High-Bandwidth Memory (HBM) Suppliers Strategic Positioning and Leadership Quadrant Report 2020 ...

Genomics England scales up genomic sequencing with Quantum ActiveScale object storage ...

NVIDIA to acquire Arm for $40 billion, creating world's premier computing company for the age of AI ...

Applications

NCSA and University of Illinois announce new Center for AstroPhysical Surveys ...

Lead lab selected for next-generation cosmic microwave background experiment ...

Insilico announces the launch of AI-powered COVIDomic to support COVID-19 research worldwide ...

Model shows that the speed neurons fire impacts their ability to synchronize ...

Physicists achieve tunable spin wave excitation ...

EBRAINS makes bid to enter the European Research Infrastructure Roadmap with ten-country strong coalition and France as lead country ...

Mysterious cellular droplets come into focus ...

The presence of resonating cavities above sunspots has been confirmed ...

The Hospital Clínic and BSC will use artificial intelligence to predict the evolution of patients with COVID-19 ...

ORIGINS - answers to existential questions ...

Altair announces 2020 Global Technology Conference to explore "The Future of..." ...

The Cloud

National Science Foundation-funded CloudBank now operational ...

Schlumberger, IBM and Red Hat announce major hybrid Cloud collaboration for the energy industry ...

Red Hat Marketplace aims to accelerate open hybrid Cloud innovation with certified software solutions ready to run on any Cloud ...

Renesas introduces DDR5 data buffer for high-performance server and Cloud service applications ...

NETINT deploys video transcoding technology in the Nimbix Cloud ...