Exponential progress in Complementary Metal Oxide Semiconductor (CMOS) miniaturization (Moore's Law) over decades has increased computing power to the point that it has transformed science and engineering and touched every aspect of modern society. Continuing progress in computing at the same rate for several more decades is likely to have an even greater impact than that seen so far. Unfortunately, over the last decade, Moore's Law has become increasingly threatened by fundamental design and manufacturing limitations that are being reached. In particular, as individual CMOS logic elements have become smaller, they have also become more sensitive to noise and interference. Moreover, CMOS elements consume power disproportionate to their size; supplying this power, dissipating the heat generated, and containing the adverse effects of high temperatures all constitute serious roadblocks to Moore's Law.
This project on PHase based LOGic using Oscillatory Nano-systems (PHLOGON) aims to circumvent these problems via a fundamentally different physical paradigm for computing: the bits and bytes that constitute digital information are encoded using the phase (or timing) of oscillatory (i.e., undulating) signals, not as voltage levels as in conventional computing. Phase encoding has inherent noise immunity advantages over level encoding; PHLOGON exploits this feature fully within the most basic elements that store and manipulate data bits. The core of PHLOGON is logic made of self-sustaining nonlinear oscillators (i.e., elements that generate their own undulating signals, like pendulum clocks). Such oscillatory logic elements can be realized easily using not only CMOS transistors, but also devices from biology such as neurons and intracellular oscillators, from nanotechnology such as Spin Torque Nano Oscillators (STNO) and Micro/Nano-Electro-Mechanical (M/NEMS) resonators, and from optics such as lasers. Thus, PHLOGON enables a wide variety of novel "substrates" for computing. Importantly, several of these (e.g., CMOS and STNOs) offer the promise of dramatically lower power/energy consumption than conventional level-based logic. By developing the core knowledge required for phase-based alternatives to level-based computing to be viable, the PHLOGON project can have significant and wide-ranging impact, potentially reversing the slow-down in Moore's Law and enabling progress in the physical mechanisms that underlie computing for decades to come.