Realization of reliable and flexible logic gates using noisy nonlinear circuits

It was shown recently [Murali et al.. Phys. Rev. Lett. 102, 104 101 (2009)] that when one presents two square waves as input to a two-state system, the response of the system can produce a logical output (NOMR) with a probability controlled by the inter-play between the system noise and the nonlinearity (that characterizes the bistable dynamics). One call switch or morph the output into another logic operation (NAND/AND) whose probability displays analogous behavior; the switching is accomplished via a controlled symmetry-breaking dc input. Thus, the interplay of nonlinearity and noise yields flexible and reliable logic behavior, and the natural outcome is, effectively, a logic gate. This logical stochastic resonance is demonstrated here via a circuit implementation using a linear resistor, it linear capacitor and four CMOS-transistors with it battery to produce a cubiclike nonlinearity. This circuit is simple, robust, and capable of operating in very high frequency regimies, further, its ease of implementation with integrated circuits and nanoelectronic devices should prove very useful in the context of reliable logic gate implementation in the presence of circuit noise. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3245318]