Double-Free-Layer Magnetic Tunnel Junctions for Probabilistic Bits

Abstract

Computers built of naturally probabilistic bits, as envisioned by Richard Feynman, share a large class of the applications anticipated for noisy intermediate-scale quantum (NISQ) computers. The authors show how the basic building block of a highly scaled memory technology, namely the familiar magnetic tunnel junction, can be straightforwardly modified by making use of two free layers that are each in the superparamagnetic regime, such that their natural fluctuations create highly efficient probabilistic bits at room temperature. The key insights obtained here may help to repurpose existing memory chips to build massively parallel probabilistic computers, with up to billions of p-bits.