Abstract
Magnetic tunnel junctions (MTJs) with low thermal stability at room temperature have been proposed as read units in beyond CMOS computing architectures including stochastic computing unit and probabilistic-bit (p-bit). Networks of multiple interconnected MTJs may face challenges due to potential device-to-device variations in thermal stability from design targets. Recently, we generated tunable telegraphic signals using a thermally stable MTJ through proper control over an external bias field and a dc voltage bias, where we showed that the average dwell times in the antiparallel (AP) and parallel states could be tuned separately. The implication for this method for p-bit designs is that it allows for p-bits to be compatible with the state-of-the-art magnetoresistive random-access memory (MRAM) technology and introduces a second degree of tunability to the input-output characteristics of the device. In this article, we expand on this method in two important ways. First, we demonstrate the applicability of our method to p-bit designs by modeling the transfer function using the existing p-bit models. Our results indicate that the transfer function can be adjusted with slight modifications to the bias field, which allows for the possibility of p-bit circuits capable of on-chip corrections against device-to-device variations in their thermal stabilities. Second, we identify the physical mechanisms that allow for two degrees of tunability in the output signal, which is explained through the Néel-Brown model. This article provides both applicability and predictability to the dual-biasing method.
Original language | English (US) |
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Article number | 8894522 |
Pages (from-to) | 5353-5359 |
Number of pages | 7 |
Journal | IEEE Transactions on Electron Devices |
Volume | 66 |
Issue number | 12 |
DOIs | |
State | Published - Dec 2019 |
Bibliographical note
Publisher Copyright:© 1963-2012 IEEE.
Keywords
- Dwell time
- magnetic tunnel junction (MTJ)
- p-bit
- probabilistic computing
- stochastic computing
- telegraphic switching
- tunable randomness