Tunable multi-bit stochasticity in La$_{0.67}$Sr$_{0.33}$MnO$_{3}$-based probabilistic bits

Abstract: One promising approach to combat the rapidly escalating computational demands is to use networks of naturally stochastic units called probabilistic bits (p-bits). To date, hardware implementations of p-bits have predominantly relied on thermally unstable nanomagnets. However, the search continues for alternative material platforms exhibiting easily accessible, intrinsic forms of stochasticity. In this work, we demonstrate hitherto unreported p-bit functionality in epitaxial thin films of La0.67Sr0.33MnO3, a material showing an electrically triggered metal-insulator transition, grown on twin-textured LaAlO3 substrates. By leveraging the combined effects of phase and structural inhomogeneities, we show two distinct modes of voltage-tunable stochastic operation: clocked binary switching and unclocked multi-bit switching. Our findings suggest that the differences result from variations in the energy landscape near the phase transition. This tunability of the energy landscape is promising for designing diverse stochastic behavior within the same material, highlighting its potential for applications in true random number generation for cryptography and probabilistic computing.