Péter Rakyta, Zoltán Zimborás (2022.01.01 - 2022.06.31)

Eötvös University, Wigner Research Centre for Physics

Grant: NKFIH 2020-2.1.1-ED-2021-00179

Abstract: In this work we propose a novel numerical approach to decompose general quantum programs in terms of single- and two-qubit quantum gates with a CNOT gate count very close to the current theoretical lower bounds. In particular, it turns out that 15 and 63 CNOT gates are sufficient to decompose a general 3 and 4-qubit unitary, respectively, with high numerical accuracy. Our approach is based on a sequential optimization of parameters related to the single-qubit rotation gates involved in a pre-designed quantum circuit used for the decomposition. In addition, the algorithm can be adopted to sparse inter-qubit connectivity architectures provided by current mid-scale quantum computers, needing only a few additional CNOT gates to be implemented in the resulting quantum circuits.

Publications:
[1] Péter Rakyta, Zoltán Zimborás: Approaching the theoretical limit in quantum gate decomposition, Quantum 6 (2022) 710
DOI: 10.22331/q-2022-05-11-710