Unbiased random bitstream generation using injection-locked spin-torque nano-oscillators

Published

March 29, 2024

Author(s)

Nhat-Tan PHAN, Nitin Prasad, Abderrazak Hakam, Ahmed SIDI EL VALLI, Lorena Anghel, Luana Carina Benetti, Advait Madhavan, Alex Jenkins, Ricardo Ferreira, Mark Stiles, Ursula Ebels, Philippe Talatchian

Abstract

Unbiased sources of true randomness are critical for the successful deployment of stochastic unconventional computing schemes and encryption applications in hardware. Leveraging nanoscale thermal magnetization fluctuations provides an efficient and almost cost-free means of generating truly random bitstreams, distinguishing them from predictable pseudo-random sequences. However, existing approaches that aim to achieve randomness often suffer from bias, leading to significant deviations from equal fractions of 0 and 1 in the bitstreams and compromising their inherent unpredictability. This study presents a hardware approach that capitalizes on the intrinsic balance of phase noise in an oscillator injection locked at twice its natural frequency, leveraging the stability of this naturally balanced physical system. We demonstrate the successful generation of unbiased and truly random bitstreams through extensive experimentation. Our numerical simulations exhibit excellent agreement with the experimental results, confirming the robustness and viability of our approach.

Citation

Physical Review Applied

Volume

21

Issue

3

Pub Type

Journals

Download Paper

https://doi.org/10.1103/PhysRevApplied.21.034063

Local Download

Keywords

magnetic tunnel junction, spin-torque nanooscillator, random number, thermal fluctuations, stochastic processes, phase dynamics

Citation

PHAN, N. , Prasad, N. , Hakam, A. , SIDI EL VALLI, A. , Anghel, L. , Benetti, L. , Madhavan, A. , Jenkins, A. , Ferreira, R. , Stiles, M. , Ebels, U. and Talatchian, P. (2024), Unbiased random bitstream generation using injection-locked spin-torque nano-oscillators, Physical Review Applied, [online], https://doi.org/10.1103/PhysRevApplied.21.034063, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=956886 (Accessed October 10, 2025)