'Memristive' switches enable 'stateful' logic operations via material implication

摘要

The authors of the International Technology Roadmap for Semiconductors-the industry consensus set of goals established for advancing silicon integrated circuit technology-have challenged the computing research community to find new physical state variables (other than charge or voltage), new devices, and new architectures that offer memory and logic functions beyond those available with standard transistors. Recently, ultra-dense resistive memory arrays built from various two-terminal semiconductor or insulator thin film devices have been demonstrated. Among these, bipolar voltage-actuated switches have been identified as physical realizations of 'memristors' or mem-ristive devices, combining the electrical properties of a memory element and a resistor. Such devices were first hypothesized by Chua in 1971 (ref. 15), and are characterized by one or more state variables that define the resistance of the switch depending upon its voltage history. Here we show that this family of nonlinear dynamical memory devices can also be used for logic operations: we demonstrate that they can execute material implication (IMP), which is a fundamental Boolean logic operation on two variables p and q such that pIMPq is equivalent to (NOTp)ORq. Incorporated within an appropriate circuit, memristive switches can thus perform 'stateful' logic operations for which the same devices serve simultaneously as gates (logic) and latches (memory) that use resistance instead of voltage or charge as the physical state variable.%将一个记忆元件和一个电阻器的电学性质结合rn起来(比如说在一个记忆电阻器或记忆电阻装rn置中)的可能性是Leon Chua在1971年提出来rn的。直到两年前、在双极电压激发开关被发现rn是记忆电阻器的物理实现之前，它仍属于理论rn范畴。这个发现重新激发了人们对记忆电阻装rn置的兴趣；而现在，Julien Borghetti及其同事rn又发现，记忆电阻器还可进行一类基础逻辑运rn算，这些运算要求各装置同时作为逻辑元件和rn记忆元件来发挥作用。看来，人们在这方面的rn兴趣还将持续下去。