Low Power Logic Operations through Pure Spin Currents

点击翻译按钮获取中文摘要

The concept of spin-based electronics has reached a stage where it is making transformational changes in advanced science and high-efficiency technology, such as magnetoresistance field sensors, hard disk drive and magnetic random access memory. A spin is an innate quantum property of every electron, and it is already flowing within every electronic device but rarely harvested. By incorporating the spin degree of freedom into existing electronic devices such as central processing units (CPUs), they can gain novel functionalities compared to the present charge-based technologies. Furthermore, modern semiconductor electronics have reached a bottleneck in clock frequency, mainly because only limited heat dissipation is achievable. For example, Intel CPUs reached 3GHz speed a decade ago, yet has been stalled at this level ever since (while using multicore solutions) due to the thermal dissipation limits at about 4GHz. This is termed the “power wall” — the defining limit to modern CPU processing power. In contrast, spintronic devices are inherently immune to this issue, i.e., they do not create Joule heating from the diffusive nature. Therefore, devices driven with pure spin currents offer far reduced power consumption than conventional electronic devices; however, spintronic devices present other technological challenges. The limited spin transfer efficiency into and across the channels is the most important, and a fundamental understanding of the spin transport processes through various media and interfaces is critical for further developing these devices.