Year: 2024
Type: article
Abstract: The deterministic switching of spin–orbit torque (SOT) memory has long been the primary challenge for implementation. Conversely, stochastic switching has recently sparked significant interest for physically secured applications. This study investigates the effects of an external field (Hx) applied to break the SOT symmetry for deterministic switching in a Pt/Co bilayer with perpendicular anisotropy. This external field serves as a tuning mechanism to adjust the stochasticity at the intermediate state during SOT switching. It is observed that moderate Hx could lead to a substantial variation in electrical output during the repeating write/read operations. In contrast, a large Hx enables precise control over the intermediate states of the Pt/Co bilayer, effectively functioning as a memristor. The stochasticity derives from small Hx resulting from the dynamics of dendritic domain wall propagation during SOT switching. Herein, the oblique domain spiking from the initially reversed domain is notably influenced by the transverse component of SOT. Increasing Hx suppresses this oblique dendritic domain growth, allowing for controllable domain propagation and reducing stochasticity. By utilizing Hx as an external knob to tailor the stochasticity at the intermediate state, the high stochastic state can be employed as an ideal entropy source for an SOT‐based random number generator.
Source: Advanced Electronic Materials
Authors: Hao‐Kai Chang, Meng‐Chi Yang, Ssu‐Yuan Wang, Chih‐Huang Lai, Chao‐Yao Yang
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,100
OpenAlex ID: W4401500178