Using negated control signals in quantum computing circuits

Abstract

White dots have been used in the schematic representation of reversible circuits to indicate that a control variable has to be inverted to become active. The present paper argues that the use of negated control signals may also offer advantages for the realization, by reducing the number of elementary components. In the case of quantum circuits, this contributes to reduce the quantum cost. It is shown that mixed polarity Reed Muller expressions, possibly extended with Boolean disjunctions, are very helpful to design quantum computing circuits including negated control signals.