Magnetic Random Access Memory (MRAM) – Technology Times

Magnetic Random Access Memory (MRAM) technology offers substantial potential towards a next-generation universal memory architecture. However, state-of-the-art MRAMs are still fundamentally constrained by a sub-nanosecond speed limitation, which has remained a long-standing scientific challenge in spintronics R&D. In this dual PhD project, Luding Wang experimentally demonstrated a fully functional picosecond opto-MRAM building block device, by integrating ultrafast photonics with spintronics.

Have you ever experienced an unexpected shutdown of your computer, losing documents in the process that you spent hours working on? Magnetic Random Access Memory (MRAM) technology focuses on manipulating electron spin to deal with such a technical problem. Inside the MRAM bits, data is written by changing the direction of the nanomagnets. Thus, MRAM allows data to be saved durably when the power supply is interrupted, computers to start up faster and devices to consume less energy.

Over the past 25 years, two major generations of MRAM have been invented and brought to market. Early MRAMs use a magnetic field to write the bits, while advanced MRAMs implement a spin current-based method. However, the data writing process of these MRAMs has been hampered by a long-standing challenge: the speed is limited to the nanosecond regime and consumes a lot of power.

In this thesis, Luding Wang from the Physics of Nanostructures research group of the Department of Applied Physics integrates a rapid development in the field of ultrafast photonics, the femtosecond (fs) laser: the fastest stimuli commercially available for humanity to break nanosecond speed limiting, and thus make it a thousand times more energy efficient.

In this double doctorate project, researchers from the Eindhoven University of Technology (TU/e) led by prof. dr. Bert Koopmans, and the Fert Beijing Institute of Beihang University directed by prof. dr. Weisheng Zhao, showed the first proof of concept of this spintronic-photonic memory using an interdisciplinary mindset.

Inspired by femtosecond laser-induced all-optical switching (AOS) schemes in synthetic ferrimagnetic multilayers discovered by TU/e ​​in 2017, its integration with bit MRAM has emerged as a competitive route to next-generation MRAM design. From his doctorate. research, Wang reports on the design and characterization of such a “hybrid” opto-memory device, coined an opto-MRAM binary cell. It shows a world-record write speed of 20 picoseconds (ps), which is 1-2 orders of magnitude beyond current state-of-the-art MRAMs, with improved power efficiency (≈ 100 femtojoules to switch a 50×50 bit of size nm2).

This first step towards the development of an “opto-MRAM” is a very random promising start towards a unique non-volatile photonic memory. It allows direct conversion of optical information into magnetic information, without intermediate energy-intensive electronic conversion steps. Moreover, the experimental results represent an important step forward to stimulate new fundamental scientific studies that combine the fields of spintronics and photonics.

Source: This news is originally published by

Comments are closed.