Pushing the Number of Qubits Below the “Minimum”: Realizing Compact Boolean Components for Quantum Logic

Research on quantum computers has gained attention since they are able to solve certain tasks significantly faster than classical machines (in some cases, exponential speed-ups are possible). Since quantum computations typically contain large Boolean components, design automation techniques are required to realize the respective Boolean functions in quantum logic. They usually introduce a significant amount of additional qubits – a highly limited resource. In this work, we propose an alternative method for the realization of Boolean components for quantum logic. In contrast to the current state-of-the-art, we dedicatedly address the main reasons causing the additionally required qubits (namely the number of the most frequently occurring output pattern as well as the number of primary outputs of the function to be realized) and propose to manipulate the function so that both issues are addressed. The resulting methods allow to push the number of required qubits below what is currently considered the minimum.