Physics Colloquium: Spins and Nanoscale Magnets: Non-volatile Memory, Hardware AI and Quantum Control

Prof. Jayasimha Atulasimha, Virginia Commonwealth University

Abstract: Some of the challenges in energy efficient computing can potentially be addressed by the use of nanoscale magnetic devices. Towards this end, a few energy efficient approaches based on electrical field control of nanoscale magnetism are pursued in our group: (i) strain mediated switching of the magnetization of nanomagnets [1]; (ii) creation and annihilation of magnetic skyrmions using direct voltage control of magnetic anisotropy (VCMA) [2] and magnetoionic control. Such nanoscale magnetic devices have application to non-volatile memory, hardware AI and quantum control of spins.

We have shown that skyrmion mediated voltage control of nanoscale magnetic devices have potential for extremely energy efficient non-volatile memory [2] that are potentially robust to switching errors in the presence of thermal noise, material and device inhomogeneities while scaling to lateral dimensions of 20 nm and below [3]. The path to commercialization of this technology will be discussed.

Furthermore, several low Size Weight and Power (SWaP) AI hardware [4, 5] that are amenable to implement in edge/IoT devices can be enabled by nanomagnetic devices. We will specifically focus on the use of multi-state nanomagnetic devices as highly quantized synapses [4] and interacting nanomagnets for reservoir computing [5].

On the other hand, we propose the use of nanomagnetic devices to address and control spin qubits [6]. By tuning the frequency of the nanomagnet’s electric field drive to the Larmor frequency of spins, single-qubit quantum gates with fidelities approaching state-of-the-art can be implemented [6].

References
[1] Nano Letters, 16, 1069, 2016; Nano Letters, 16, 5681, 2016.
[2] Nature Electronics 3, 539, 2020.
[3] Scientific Reports,11, 20914, 2021.
[4] IEEE Access, 10, 84946, 2022;
[5] Appl. Phys. Lett. 121, 102402, 2022, Communication Physics 6, 215, 2023.
[6] Communication Physics 5, 284, 2022.

Short Bio: Jayasimha Atulasimha is an Engineering Foundation Professor of Mechanical and Nuclear Engineering with a courtesy/affiliate appointment in Electrical and Computer Engineering and Physics at the Virginia Commonwealth University. His current research interests include nanomagnetism, spintronics, non-volatile memory, hardware AI and quantum computing. He is a fellow of the ASME, an IEEE Senior Member and past chair for the Technical Committee on Spintronics, IEEE Nanotechnology Council.