Nanoscale true random bit generator based on magnetic state transitions in magnetic tunnel junctions

Alex S Jenkins,Lara San Emeterio Alvarez,Paulo P Freitas,Ricardo Ferreira

doi:10.1038/s41598-019-52236-z

Alex S Jenkins, Lara San Emeterio Alvarez + Show 2 more

Open Access

https://doi.org/10.1038/s41598-019-52236-z

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Abstract

We present an investigation into the in-plane field induced free layer state transitions found in magnetic tunnel junctions. By applying an ac current into an integrated field antenna, the magnetisation of the free layer can be switched between the magnetic vortex state and the quasi-uniform anti-parallel state. When in the magnetic vortex state, the vortex core gyrates a discrete number of times, and at certain frequencies there is a 50% chance of the core gyrating n or n − 1 times, leading to the proposal of a novel nanoscale continuous digital true random bit generator.

Highlights

We present an investigation into the in-plane field induced free layer state transitions found in magnetic tunnel junctions
A high frequency robust true random number generator with a resistive output, nanometric footprint and potential to be engineered towards ultra-low power consumption and direct CMOS integration is presented, with the potential to make meaningful impact for IoT cyber-security applications
One exciting avenue of research for emerging nanotechnology solutions is the field of spintronics

Summary

Introduction

We present an investigation into the in-plane field induced free layer state transitions found in magnetic tunnel junctions. Www.nature.com/scientificreports voltage measured at and (c) magnetisation component along the y-axis for an excitation frequency of 70 MHz, with examples of the magnetisation configuration of (i) the QUAP state and (ii) the vortex state.

Results

Conclusion