Helimagnet-based non-volatile multi-bit memory units
File(s)1448855_1_merged_1680027597.pdf (1.9 MB)
Accepted version
Author(s)
Islam, Rabiul
Li, Peng
Beg, Marijan
Sachdev, Manoj
Miao, Guo-Xing
Type
Journal Article
Abstract
In this Letter, we present a design of a helimagnet-based emerging memory device that is capable of storing multiple bits of information per device. The device consists of a helimagnet layer placed between two ferromagnetic layers, which allows us to lock-in specific spin configurations. The bottom pinned layer has high anisotropy energy or stays exchange biased, which keeps its spin configuration fixed on a specific direction, while the top layer is free to rotate under the influence of in-plane magnetic fields. We begin by finding the relaxed spin structure, which is the result of the competition between the Dzyaloshinskii–Moriya interaction (DMI) and exchange energy and is referred to as the equilibrium state (“0”). The writing of a memory state is simulated by applying an in-plane field that rotates and transforms the spin configurations of the memory device. Our results indicate that stable configurations can be achieved at rotations of an integer multiple of 180° (corresponding to states “−2,” “−1,” “1,” “2,” etc.), where the anisotropy stabilizes the free layer and, thus, the exchange coupled helimagnet. These states are separated by magnetic energy barriers and intermediate, unstable spin configurations tend to revert to their adjacent states. By simply changing the direction of the field, we can achieve multi-bit data storage per unit memory cell. The maximum number of bits is reached when the anisotropy energy barriers cannot withstand the strong DMI energy. Reading can be done by evaluating the different resistance states due to the twisted spin texture.
Date Issued
2023-04
Date Acceptance
2023-03-28
Citation
Applied Physics Letters, 2023, 122 (15), pp.1-6
ISSN
0003-6951
Publisher
American Institute of Physics
Start Page
1
End Page
6
Journal / Book Title
Applied Physics Letters
Volume
122
Issue
15
Copyright Statement
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Rabiul Islam, Peng Li, Marijan Beg, Manoj Sachdev, Guo-Xing Miao; Helimagnet-based nonvolatile multi-bit memory units. Appl. Phys. Lett. 10 April 2023; 122 (15): 152407. https://doi.org/10.1063/5.0147066
Identifier
https://pubs.aip.org/aip/apl/article/122/15/152407/2878605/Helimagnet-based-nonvolatile-multi-bit-memory
Publication Status
Published
Article Number
152407
Date Publish Online
2023-04-13