Programmable comparators based array for regular QCA Implementation

The paper presents a novel universal quantum cellular automata (QCA) gate called boundary comparator. This gate implements a Boolean function in its boundary form, which is a superposition of elementary boundary functions i.e. a threshold function having weights equal to integer powers of 2. The boundary comparators are arranged in a form of array forming homogeneous programmable structure. The paper proposes a method of synthesis of Boolean functions on the base of boundary functions. The method uses autocorrelation values of the initial function for minimization of a number of bounds. The structures of the boundary comparator as well as the structure of the comparator-based array are presented. Benchmark results allow evaluating efficiency of the proposed structure in comparison with known QCA solutions.