Spintronic devices: From memory to memristor

In 1971, Professor Leon Chua in UC Berkeley predicted the fourth fundamental passive circuit element - memristor, based on the conceptual completeness of circuit theory. 37 years later, a team at HP Labs led by Dr. Stanley Williams announced the development of the first switching memristor. From then, more and more researches on memristor are conducted at various levels. Spintronic technology was introduced to the nonvolatile memory design regime in the recent decade. For example, spin-transfer torque random access memory (STT-RAM) has demonstrated many promising characteristics such as non-volatility, zero standby power, nanosecond access time, high memory density, and good scalability. In this paper, we will give a short tutorial of our works in STT-RAM from the viewpoints of device, design and system applications. On the top of that, we will also discuss one type of memsitors based on spintronic technology (spintronic memristor), including the device modeling and the applications in sensor.