Efficient T-Count Fault-tolerant Quantum Clifford+T Multiplexer
Negin Mashayekhi, Shekoofeh Moghimi, Mohammad Reza Reshadinezhad
Reversible logic is essential in quantum computing due to its ability to preserve information and establish a one-to-one mapping between inputs and outputs. The Clifford+T gate set, known for supporting fault-tolerant quantum circuits, offers resilience against decoherence but introduces high implementation costs, particularly due to the T gate's resource intensity. In this work, we propose a new and efficient quantum multiplexer design, the Quantum Clifford T-MUX, designed entirely within the Clifford+T framework. This multiplexer minimizes T-count and avoids the use of ancillary qubits, both critical factors for practical, fault-tolerant quantum computing. As part of this architecture, we present a newly designed fault-tolerant Peres gate using only Clifford+T gates, which serves as a fundamental building block in the T-MUX construction. The proposed T-MUX achieves reduced T-count, no garbage output, and improved efficiency compared to traditional designs. These improvements position it as a valuable component for building scalable quantum Arithmetic Logic Units (ALUs), data buses, and memory systems. Overall, this work contributes toward the development of low-overhead, modular quantum control structures suited for near-term and long-term quantum computing architectures. The proposed circuit is simulated using the Quirk online tool, and the result confirms the accuracy of the design. This design achieves an average 35% improvement in T-Count without any constant input, compared to its counterpart, respectively.
International Conference on Computer and Knowledge Engineering•Oct 28, 2025•0 citations