I will describe a novel numerical approach to decompose quantum programs in terms of single- and two-qubit quantum gates with close-to-optimal CNOT gate count[1]. In particular, it turns out that 15 and 63 CNOT gates are sufficient to decompose a general 3- and 4-qubit unitary, respectively. In addition, the algorithm can be adapted to sparse inter-qubit connectivity architectures provided by current intermediate-scale quantum computers, needing only few additional CNOT gates to be implemented in the resulting quantum circuits. I will provide a benchmark comparison of the SQUANDER package implementing our algorithm with the state-of-the-art quantum synthesis tools by decomposing quantum programs accessible in online databases.

 

[1] P. Rakyta and Z. Zimboras, “Sequential quantum gate decomposer (SQUANDER),” 2021. [Online].

Available: https://doi.org/10.5281/zenodo.4508680