common digital integrated circuits built today use CMOS logic, which is fast, offers high circuit density and low power per gate. This is used even in large, fast computers, such as the IBM System z. Recent developments In 2009, researchers discovered that memristors can implement a boolean state storage and provides a complete logic family with very small amounts of space and power, using familiar CMOS semiconductor processes. The discovery of superconductivity has enabled the development of rapid single flux quantum (RSFQ) circuit technology, which uses Josephson junctions instead of transistors. Most recently, attempts are being made to construct purely optical computing systems capable of processing digital information using nonlinear optical elements. See also De Morgan's laws Logical effort Logic optimization Microelectronics Unconventional computing Notes References Further reading Douglas Lewin, Logical Design of Switching Circuits, Nelson,1974. R. H. Katz, Contemporary Logic Design, The Benjamin/Cummings Publishing Company, 1994. P. K. Lala, Practical Digital Logic Design and Testing, Prentice Hall, 1996. Y. K. Chan and S. Y. Lim, Progress In Electromagnetics Research B, Vol. 1, 269–290, 2008, "Synthetic Aperture Radar (SAR) Signal Generation, Faculty of Engineering & Technology, Multimedia University, Jalan Ayer Keroh Lama, Bukit Beruang, Melaka 75450, Malaysia. External links Digital Circuit Projects: An Overview of Digital Circuits Through Implementing Integrated Circuits (2014) MIT OpenCourseWare introduction to digital design class materials ("6.004: Computation Structures") Electronic design Electronic design automation