Technology Mapping of Reversible Circuits to Clifford plus T Quantum Circuits

The Clifford+T quantum gate library has attracted much interest in the design of quantum circuits, particularly since the contained operations can be implemented in a fault-tolerant manner. Since fault tolerant implementations of the T gate have very high latency, synthesis and optimization are aiming at minimizing the number of T stages, referred to as the T-depth. In this paper, we present an approach to map mixed polarity multiple controlled Toffoli gates into Clifford+T quantum circuits. Our approach is based on the multiple control Toffoli mapping algorithms proposed by Barenco et al., which are given T-depth optimized Clifford+T translations. Experiments show that our approach leads to a significant T-depth reduction of 54% on average.