Memory | Spintronics-Info

Researchers develop a simple MRAM structure based on unidirectional spin hall magnetoresistance (USMR)

Researchers from the Tokyo Institute of Technology (Tokyo Tech) developed a new MRAM cell structure that relies on unidirectional spin Hall magnetoresistance (USMR). The new cell structure is reportedly very simple with only two layers which could lead to lower-cost MRAM devices.

USMR MRAM cell structure image

The spin Hall effect leads to the accumulation of electrons with a certain spin on the lateral sides of a material. By combining a topological insulator with a ferromagnetic semiconductor, the researchers managed to create a device with giant USMR.

Quantum Well structures can enhance the TMR of MTJs

Researchers from Japan's National Institute for Materials Science (NIMS) have managed to introduce a quantum well structure into a conventional magnetic tunnel junction (MTJ). The researchers say that the QW structure can enhance the tunneling magnetoresistance (TMR) ratio by spin-dependent resonant tunnel (SDRT) effect, with a value of 1.5 times comparing with no SDRT case, at room temperature.

Quantum Well structure introduced to MTJs (NIMS)

The researchers tell us that the key point of the QW formation is the band mismatch between Cr and Fe for majority band, and the mismatch-free Fe/MgAl₂O₄ interface. The finding is not just useful for enhancement of TMR ratio, it also provides a benefit that the TMR ratio could be kept almost constant in a wide bias voltage range of from -1V to 0.5V.

Optically-assisted MRAM could be a thousand time more efficient then current MRAM devices

Researchers from the Moscow Institute of Physics and Technology, in collaboration with researchers from Germany and the Netherlands have developed a new memory technology they call optically-assisted MRAM which is based on changing the spin state via THz pulses.

The researchers say that the new technique is extremely efficient (the power required to switch a "bit" will be a thousand times smaller compared to current MRAM devices) and fast.

Researchers announce a breakthrough in pinning domain wall propagation

Researchers from Sultan Qaboos University in Oman, Johannes Gutenberg-Universität Mainz in Germany and Nanyang Technological University in Singapore have experimentally demonstrated a breakthrough in one of the major problems blocking the adoption of magnetic domain wall memory.

When recording each fresh bit of information onto a racetrack, there is considerable uncertainty about where each magnetic domain starts and ends, and an incorrectly-written bit can easily lead to the corruption of bits. The team, led by Professor Rachid Sbiaa of Sultan Qaboos University, devised a method to overcome this difficulty by using a staggered nanowire (see figure below).

Researchers develop a 200Mhz spintronics-based microcontroller unit

Researchers from Japan's Tohoku University have developed a nonvolatile microcontroller unit (MCU) which achieves both high performance and ultra-low power by utilizing spintronics-based VLSI design technology and STT-MRAM memory.

Spintronics 200Mhz MCU (Tohoku University) photo
The researchers used several new techniques to create an efficient and fast device. Each module's power supply is controlled independently, which eliminates wasteful power consumption, while a memory controller and a reconfigurable accelerator module are used to relax data transfer bottlenecks. These new techniques enabled the researchers to achieve ultra-lower power consumptioN (47.14 uW) at 200Mhz.

EU researchers fabricated graphene-based spintronics devices that utilize both electron charge and spin at room temperature

EU's Graphene Flagship project researchers fabricated graphene-based spintronics devices that utilize both electron charge and spin at room temperature.

The researchers demonstrated the spin’s feasibility for bridging distances of up to several micrometres - which they say could open the door to single-chip devices that integrate logic and memory.

Researchers in the UK explore 2D hBN as a material for spin valves and MTJs

Researchers from the UK's Manchester University have explored opportunities presented by hexagonal boron nitride (hBN) as a prototypical high-quality two-dimensional insulator that can be used both as a barrier in MTJs and as for spin injection in lateral spin valves.

The research revealed the effect of point defects inevitably present in mechanically exfoliated hBN on the tunnel magnetoresistance of Co-hBN-NiFe MTJs. In particular, the researchers observe a marked enhancement of the magnetoresistance of the junction at well-defined bias voltages, indicating resonant tunneling through magnetic or 'spin-polarized' defect states.

The US NIST to establish a $10 million spintronics material research facility in Minnesota

The US National Institute of Standards and Technology (NIST) and its partners in the US Nanoelectronic Computing Research (nCORE) consortium have awarded $10.3 million over four years to establish a spintronics research center in Mineesota.

The Center for Spintronic Materials in Advanced Information Technologies (SMART) will be led by and housed at the University of Minnesota Twin Cities and will include researchers from the Massachusetts Institute of Technology, Pennsylvania State University, Georgetown University and the University of Maryland.

Researchers manage to produce promising Bismuth Selenide films using sputtering

Researchers from the University of Minnesota have managed to deposit Bismuth Selenide (Bi₂Se₃) films using a simple sputtering technique.

Bismuth Selenide is topological insulator and a promising material for spintronics applications including MRAM devices. The material produced in this research featured a high spin torque at room temperatures.

BiSb films feature a colossal spin hall effect and high electrical conductivity

Researchers from the Tokyo Institute of Technology have developed a new thin film material made from bismuth-antimony (BiSb) that is a topological insulator that simultaneously achieves a colossal spin Hall effect and high electrical conductivity.

This material could be used as the basis of spin-orbit torque MRAM (SOT-MRAM). SOT-MRAM SOT-MRAM can overcome the limitation of spin-transfer torque in MRAM memories - and provide a much faster, denser and much more efficient memory technology. Up until now, though, no suitable material that features both high electrical conductivity and a high spin hall effect was developed.