Quantum Materials Enable Energy-Efficient Spintronic Memories

Memory is a fundamental component of computers, crucial for data storage, caching, buffering, and in-memory computing. Due to varying sizes, speeds, and storage capacities, different memory devices are in use today, and the search for a universal solution continues. One innovative non-volatile memory approach employs the spin angular momentum of electrons to switch the magnetization of materials, representing data as ones and zeros.

Over the past decade, such magnetic memory technologies have evolved significantly, with each generation offering enhanced performance and efficiency. The current generation of magnetic random-access memory (MRAM) utilizes spin-transfer torque (STT) technology, where a spin-polarized current is used to electrically control magnetization in nanoscale devices. This technology has gained traction in space, automotive, robotics, and defense applications. However, for MRAM to serve as a universal memory, it must be faster, more energy-efficient, and have greater endurance.

Spin-orbit torque (SOT) MRAM is an emerging alternative offering lower energy consumption, higher speed, and durability. SOT-MRAM switches magnetic orientations using current-induced SOT. However, traditional SOT materials generate only in-plane spin currents, which are inefficient for high-density memory applications. Thus, discovering new materials with strong out-of-plane spin polarization and SOT components is crucial.

Out-of-plane spin polarization and SOT

In a recent study published in the journal Nature Communications, Prof. Saroj Dash, leader of a group on Quantum Device Physics at Chalmers University of Technology and WISE researcher, in collaboration with researchers from Gothenburg University, Uppsala University, University of Shariah, the Indian Institute of Technology, and Tohoku University, demonstrated a significant out-of-plane damping-like SOT at room temperature using the topological Weyl semimetal candidate, TaIrTe4.

–In a two-dimensional Weyl semimetal, the presence of unique band crossings in momentum space and novel topological spin textures gives a variety of unusual electronic and charge-to-spin conversion properties. We showed that the combination of topological spin textures, and lower crystal symmetry makes TaIrTe a promising candidate for energy-efficient SOT devices, says Prof. Dash.

Dr. Lakhan Bainsla, researcher in the group of Prof. Dash and first author of the publication, observed a significant out-of-plane SOT and a substantial out-of-plane spin Hall conductivity at room temperature, demonstrating their potential for energy-efficient switching of an out-of-plane magnet without the need for an external magnetic field. This breakthrough in out-of-plane SOT holds great promise for advancing spintronic memory, logic circuits, high-frequency magnetic devices, and neuromorphic computing applications, potentially revolutionizing these technologies.

The article published in Nature Communications entitled “Large out-of-plane spin-orbit torque in topological Weyl semimetal TaIrTe4” can be found at: https://www.nature.com/articles/s41467-024-48872-3

To learn more about Professor Dash’s WISE research please visit:

2D Quantum Materials for Sustainable Information Technologies