Polylogarithmic-depth controlled-NOT gates without ancilla qubits

Authors: Baptiste Claudon, Julien Zylberman, César Feniou, Fabrice Debbasch, Alberto Peruzzo, Jean-Philip Piquemal

Published: 2024-07-13

DOI: 10.1038/s41467-024-50065-x

Source: Full article


Abstract

AbstractControlled operations are fundamental building blocks of quantum algorithms. Decomposing n-control-NOT gates (Cn(X)) into arbitrary single-qubit and CNOT gates, is a crucial but non-trivial task. This study introduces Cn(X) circuits outperforming previous methods in the asymptotic and non-asymptotic regimes. Three distinct decompositions are presented: an exact one using one borrowed ancilla with a circuit depth $$\Theta (\log {(n)}^{3})$$