Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International

Wikipedia Affiliate Button

Home > Press > Paving the way for spintronic RAMs: A deeper look into a powerful spin phenomenon

The proposed combination of materials serves as a memory unit by supporting read and write operations. The spin injection by the topological insulator (TI) material reverses the magnetization of the ferromagnetic (FM) material, representing the 'write' operation. Furthermore, the spin injection can also change the overall resistance of the materials, which can be sensed through an external circuit, representing the 'read' operation.

CREDIT
Journal of Applied Physics
The proposed combination of materials serves as a memory unit by supporting read and write operations. The spin injection by the topological insulator (TI) material reverses the magnetization of the ferromagnetic (FM) material, representing the 'write' operation. Furthermore, the spin injection can also change the overall resistance of the materials, which can be sensed through an external circuit, representing the 'read' operation. CREDIT Journal of Applied Physics

Abstract:
Scientists at Tokyo Institute of Technology(Tokyo Tech) explore a new material combination that sets the stage for magnetic random access memories, which rely on spin--an intrinsic property of electrons-- and could outperform current storage devices. Their breakthrough published in a new study describes a novel strategy to exploit spin-related phenomena in topological materials, which could spur several advances in the field of spin electronics. Moreover, this study provides additional insight into the underlying mechanism of spin-related phenomena.

Paving the way for spintronic RAMs: A deeper look into a powerful spin phenomenon

Tokyo, Japan | Posted on December 27th, 2019

Spintronics is a modern technological field where the "spin" or the angular momentum of electrons takes a primary role in the functioning of electronic devices. In fact, collective spin arrangements are the reason for the curious properties of magnetic materials, which are popularly used in modern electronics. Researchers globally have been trying to manipulate spin-related properties in certain materials, owing to a myriad of applications in devices that work on this phenomenon, especially in non-volatile memories. These magnetic non-volatile memories, called MRAM, have the potential to outperform current semiconductor memories in terms of power consumption and speed.

A team of researchers from Tokyo Tech, led by Assoc. Prof. Pham Nam Hai, recently published a study in Journal of Applied Physics on unidirectional spin Hall magnetoresistance (USMR), a spin-related phenomenon that could be used to develop MRAM cells with an extremely simple structure. The spin Hall effect leads to the accumulation of electrons with a certain spin on the lateral sides of a material. The motivation behind this study was that the spin Hall effect, which is particularly strong in materials known as "topological insulators", can results in a giant USMR by combining a topological insulator with a ferromagnetic semiconductor.

Basically, when electrons with the same spin accumulate on the interface between the two materials, (Fig. 1) due to the spin Hall effect, the spins can be injected to the ferromagnetic layer and flip its magnetization, allowing for "memory write operations", which means the data in storage devices can be "re-written". At the same time, the resistance of the composite structure changes with the direction of the magnetization owing to the USMR effect. Because resistance can be measured using an external circuit, this allows for "memory read operations", in which data can be read using the same current path with the write operation. In existing material combination using conventional heavy metals for the spin Hall effect, however, the changes in resistance caused by the USMR effect are extremely low--well below 1%--which hinders the development of MRAMs utilizing this effect. In addition, the mechanism of the USMR effect seems to vary according to the combination of material used, and it is not clear which mechanism can be exploited for enhancing the USMR to over 1%.

To understand how material combinations can influence the USMR effect, the researchers designed a composite structure comprising a layer of gallium manganese arsenide (GaMnAs, a ferromagnetic semiconductor) and bismuth antimonide (BiSb, a topological insulator). Interestingly, with this combination, they were successful in obtaining a giant USMR ratio of 1.1%. In particular, the results showed that utilizing phenomena called "magnon scattering" and "spin-disorder scattering" in ferromagnetic semiconductors can lead to a giant USMR ratio, making it possible to use this phenomenon in real-world applications. Dr. Hai elaborates, "Our study is the first to demonstrate that it is possible to obtain an USMR ratio larger than 1%. This is several orders of magnitude higher than those using heavy metals for USMR. In addition, our results provide a new strategy to maximize the USMR ratio for practical device applications".

This study could play a key role in the development of spintronics. Conventional MRAM structure requires about 30 ultrathin layers, which is very challenging to make. By utilizing USMR for read-out operation, only two layers are needed for the memory cells. "Further material engineering may further improve the USMR ratio, which is essential for USMR-based MRAMs with an extremely simple structure and fast reading. Our demonstration of an USMR ratio over 1% is an important step toward this goal," concludes Dr. Hai.

####

For more information, please click here

Contacts:
Emiko Kawaguch

81-357-342-975

Copyright © Tokyo Institute of Technology

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

RELATED JOURNAL ARTICLE:

Related News Press

News and information

Let the europium shine brighter January 21st, 2020

Nanotubes may give the world better batteries: Rice U. scientists' method quenches lithium metal dendrites in batteries that charge faster, last longer January 16th, 2020

Quantum physics: Controlled experiment observes self-organized criticality January 16th, 2020

Pretty with a twist: Complex porous, chiral nano-patterns arise from a simple linear building block January 16th, 2020

Possible Futures

Let the europium shine brighter January 21st, 2020

Study finds billions of quantum entangled electrons in 'strange metal' Physicists provide direct evidence of entanglement's role in quantum criticality January 16th, 2020

Nanotubes may give the world better batteries: Rice U. scientists' method quenches lithium metal dendrites in batteries that charge faster, last longer January 16th, 2020

Researchers gain control over internal structure of self-assembled composite materials January 16th, 2020

Spintronics

Generation and Manipulation of spin currents for advanced electronic devices January 9th, 2020

How to induce magnetism in graphene: Elusive molecule predicted in the 1970s finally synthesized December 11th, 2019

Toward more efficient computing, with magnetic waves: Circuit design offers a path to 'spintronic' devices that use little electricity and generate practically no heat November 29th, 2019

A distinct spin on atomic transport: Work that demonstrates simultaneous control over transport and spin properties of cold atoms establishes a framework for exploring concepts of spintronics and solid-state physics November 8th, 2019

Chip Technology

Toward safer disposal of printed circuit boards January 16th, 2020

Generation and Manipulation of spin currents for advanced electronic devices January 9th, 2020

NUS scientists create world’s first monolayer amorphous film January 9th, 2020

Onto Innovation to Present at the 22nd Annual Needham Growth Conference January 3rd, 2020

Memory Technology

Generation and Manipulation of spin currents for advanced electronic devices January 9th, 2020

Electro-optical device provides solution to faster computing memories and processors: First-of-a-kind electro-optical device provides solution to faster and more energy efficient computing memories and processors December 2nd, 2019

Small, fast, and highly energy-efficient memory device inspired by lithium-ion batteries November 22nd, 2019

A modified device fabrication process achieves enhanced spin transport in graphene August 6th, 2019

Discoveries

Let the europium shine brighter January 21st, 2020

Quantum physics: Controlled experiment observes self-organized criticality January 16th, 2020

Pretty with a twist: Complex porous, chiral nano-patterns arise from a simple linear building block January 16th, 2020

Toward safer disposal of printed circuit boards January 16th, 2020

Announcements

Let the europium shine brighter January 21st, 2020

Quantum physics: Controlled experiment observes self-organized criticality January 16th, 2020

Pretty with a twist: Complex porous, chiral nano-patterns arise from a simple linear building block January 16th, 2020

Toward safer disposal of printed circuit boards January 16th, 2020

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters

Let the europium shine brighter January 21st, 2020

Quantum physics: Controlled experiment observes self-organized criticality January 16th, 2020

Pretty with a twist: Complex porous, chiral nano-patterns arise from a simple linear building block January 16th, 2020

Toward safer disposal of printed circuit boards January 16th, 2020

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project