Optimizing Qubit Routing with Bridge Gates: Extending Quantum Circuit Efficiency Across Arbitrary Distances
conference paper
Qubit routing is a critical challenge in quantum computing, essential for implementing quantum circuits on hardware with limited connectivity. This paper introduces a novel perspective on qubit routing by exploring the use of bridge gates, which enable the execution of controlled NOT (CNOT) operations over non-adjacent qubits without rerouting the qubits. The study highlights the advantages of bridge gates compared to SWAP gates, particularly their ability to preserve qubit assignments and potentially optimize subsequent routing steps. We propose an extension to the concept of bridge gates by generalizing them for arbitrary distances and provide constructions demonstrating their feasibility. By analysing their performance, we show that largerdistance bridge gates can significantly reduce the number of CNOT gates in certain circuits. Furthermore, a new qubit routing problem is defined, incorporating both SWAP and bridge gates, and we discuss how this impacts the complexity of the problem.
TNO Identifier
1023873
Publisher
Springer
Source title
QUEST-IS 2025 Quantum Engineering Sciences & Technologies for Industry & Services, 1-4 December 2025
Pages
301-310
Files
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