Guide to Spintronic Crossbar Arrays: From Binary Switches to Analog Computing

Spintronic crossbar arrays are emerging as a powerful hardware platform for energy-efficient computing. Unlike conventional digital processors that shuttle data between memory and processing units, these arrays perform computation directly where data is stored, a concept known as in-memory computing. This report explains, from the ground up, what spintronic crossbars are, how they operate, and the different types currently available or under development. We cover both binary (single-level) and analog (multi-level) devices, their input/output characteristics, and the physical principles that make them uniquely suited for matrix operations. The figures illustrate the architecture, switching mechanisms, and the transition from binary to multi-level behavior. This foundation is essential for understanding advanced applications such as parallel photovoltaic MPPT and neuromorphic computing.