Interspecies Förster resonances for Rb-Cs Rydberg d -states for enhanced multi-qubit gate fidelities

We present an analysis of interspecies interactions between Rydberg <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mi>d</a:mi></a:math>-states of rubidium and cesium. We identify the Förster resonance channels offering the strongest interspecies couplings, demonstrating the viability for performing high-fidelity two- and multi-qubit <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mrow><b:msub><b:mi>C</b:mi><b:mi>k</b:mi></b:msub><b:mi>Z</b:mi></b:mrow></b:math> gates up to <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mrow><c:mi>k</c:mi><c:mo>=</c:mo><c:mn>4</c:mn></c:mrow></c:math>, including accounting for blockade errors evaluated via numerical diagonalization of the pair potentials. Our results show <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"><d:mi>d</d:mi></d:math>-state orbitals offer enhanced suppression of intraspecies couplings compared to <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"><e:mi>s</e:mi></e:math>-states, making them well suited for use in large-scale neutral atom quantum processors. Published by the American Physical Society 2024