Spin current

Researchers examine new ways to excite spin waves with infrared light

Researchers have devised a new ultrafast method for controlling magnetic materials, that may enable next-generation information processing technologies.

A possible solution for building faster systems for processing is to use patterns of electron spins, called spin waves, to transfer and process information much more rapidly than in conventional computers. So far, a major challenge has been in manipulating these ultrafast spin waves to do useful work. Announcing a significant step forward, researchers from The University of Texas at Austin and MIT have developed a method to precisely manipulate these ultrafast spin waves using tailored light pulses. Their findings are detailed in two studies in Nature Physics, led by MIT graduate student Zhuquan Zhang, University of Texas at Austin postdoctoral researcher Frank Gao, MIT’s professor of chemistry Keith Nelson and UT Austin assistant professor of physics Edoardo Baldini.

Read the full story Posted: Feb 01,2024

Researchers induce robust spin-polarization in graphene for low-power electronics

Researchers at the National University of Singapore (NUS), University of Science and Technology of China and the National Institute for Materials Science in Japan have developed a way to induce and directly quantify spin splitting in two-dimensional materials. 

Using this concept, they have experimentally achieved large tunability and a high degree of spin-polarization in graphene. This research achievement can potentially advance the field of two-dimensional (2D) spintronics, with applications for low-power electronics.

Read the full story Posted: Nov 25,2023

Researchers observe and control spin waves in magnets with superconductors

Scientists at Delft University of Technology have used superconducting diamagnetism to shape the magnetic environment governing the transport of spin waves—collective spin excitations in magnets that are promising on-chip signal carriers—in a thin-film magnet. 

The team has shown that it’s possible to control and manipulate spin waves on a chip using superconductors for the first time. These tiny waves in magnets may offer an alternative to electronics in the future, interesting for energy-efficient information technology or connecting pieces in a quantum computer, for example. The results of this work give scientists new insight into the interaction between magnets and superconductors.

Read the full story Posted: Oct 28,2023

Researchers show that topological materials may open the door to exploring spin hall materials

Researchers from Tohoku University, Chinese Academy of Sciences (CAS), Guangxi Normal University, Kyushu University and Japan Atomic Energy Agency have reported a significant breakthrough which could revolutionize next-generation electronics by enabling non-volatility, large-scale integration, low power consumption, high speed, and high reliability in spintronic devices.

Spintronic devices, such as magnetic random access memory (MRAM), utilize the magnetization direction of ferromagnetic materials for information storage and rely on spin current, a flow of spin angular momentum, for reading and writing data. Conventional semiconductor electronics have faced limitations in achieving these qualities. However, the emergence of three-terminal spintronic devices, which employ separate current paths for writing and reading information, presents a solution with reduced writing errors and increased writing speed. Nevertheless, the challenge of reducing energy consumption during information writing, specifically magnetization switching, remains a critical concern.

Read the full story Posted: Sep 23,2023

Researchers manipulate the edge-states of a topological insulator to reveal materials with ‘two way’ edge transport

Researchers from Monash University in Australia have shown in their recent theoretical study that ‘trimming’ the edge-states of a topological insulator can yield a new class of materials featuring unconventional ‘two way’ edge transport.

The new material, a topological crystalline insulator (TCI) forms a promising addition to the family of topological materials and broadens the scope of materials with topologically nontrivial properties. Its distinctive reliance on symmetry also paves the way for novel techniques to manipulate edge transport, offering potential applications in future transistor devices. For example, ‘switching’ the TCI via an electric field that breaks the symmetry supporting the nontrivial band topology, thus suppressing the edge current.

Read the full story Posted: Aug 22,2023

Scientists predict "parallel circuits" of spin currents in antiferromagnets

A group of physicists, led by Prof. SHAO Dingfu from the Hefei Institutes of Physical Science (HFIPS) of the Chinese Academy of Sciences (CAS), has predicted "parallel circuits" of spin currents in antiferromagnets, which can accelerate spintronics.

Spin-polarized electric currents play a central role in spintronics, due to the capabilities of manipulation and detection of magnetic moment directions for writing and reading 1s and 0s. Currently, most spintronic devices are based on ferromagnets, where the net magnetizations can efficiently spin polarize electric currents. Antiferromagnets, with opposite magnetic moments aligned alternately, are not quite as investigated but may promise even faster and smaller spintronic devices.

Read the full story Posted: Jun 11,2023

Researchers demonstrate method for inducing and controlling the flow of spin and valley currents in ultrafast timeframes using laser pulses

Researchers at the Max Born Institute in Germany recently discovered a method for inducing and controlling the flow of spin and valley currents in ultrafast timeframes, using specially designed laser pulses. This discovery could offer a novel perspective on the search for the next generation of information technologies.

Ultrafast laser control over the basic quantum properties of matter is a critical challenge that must be addressed to develop future information technologies beyond the semiconductor electronics that define our current era. Electron spin and valley index, an emergent property of two-dimensional materials related to quasiparticle momentum, are two promising quantum properties in this regard. Both spintronics and valleytronics offer many potential advantages over classical electronics in terms of data manipulation speed and energy efficiency. While spin excitations suffer from a dynamic loss of character due to spin-orbit-induced spin precession, the valley wavefunction represents a more stable "data bit" that is only threatened by intervalley scattering, a feature controllable by sample quality. Valleytronics thus presents a potentially robust platform for moving beyond classical electronics.

Read the full story Posted: Apr 15,2023

Researchers review achievements in antiferromagnetic spintronics

Researchers from Tohoku University, University of California Riverside and Massachusetts Institute of Technology (MIT) have highlighted a series of critical achievements in antiferromagnetic spintronics (including their own contributions), revealing an emerging frontier distinguished by the coherent spin dynamics of antiferromagnets. 

Within antiferromagnetic spintronics, scientists have exerted a lot of efforts on the switching and readout of static magnetic order. But coherent spin dynamics, the key to exploring the wave features of spins and integrating spintronics with quantum and neuromorphic technologies, has only received attention very recently. "The coherent spin dynamics of antiferromagnets exhibits a lot more intriguing features than that of ferromagnets," says Jiahao Han, a JSPS Research Fellow working at the Research Institute of Electrical Communication (RIEC), Tohoku University. "By harnessing this unique property, the team has been pursuing breakthroughs that eventually form a new chapter named coherent antiferromagnetic spintronics."

Read the full story Posted: Mar 27,2023

Researchers improve the light–matter interaction by coupling terahertz light with spin waves

An international research team led by the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) has developed a new method for the efficient coupling of terahertz waves with much shorter wavelengths, so-called spin waves.

The team's experiments, in combination with theoretical models, clarify the fundamental mechanisms of this process previously thought impossible. The results are an important step for the development of novel, energy-saving spin-based technologies for data processing.

Read the full story Posted: Feb 02,2023

Researchers detect and map non-linear spin waves

Researchers from Germany's Martin Luther University Halle-Wittenberg (MLU) have demonstrated that strong alternating magnetic fields can be used to generate a new type of spin wave. This is the first time this was accomplished as the phenomenon was previously only theoretically predicted. Thee team reported on their work and provided the first microscopic images of these spin waves.

The basic idea of spintronics is to use a special property of electrons (spin) for various electronic applications. The Spin is the intrinsic angular momentum of electrons that produces a magnetic moment. Coupling these magnetic moments creates the magnetism that could ultimately be used in information processing. When these coupled magnetic moments are locally excited by a magnetic field pulse, this dynamic can spread like waves throughout the material. These are referred to as spin waves or magnons.

Read the full story Posted: Sep 16,2022