Rubidium

Rubidium (Rb) is an alkali metal whose neutral atoms can be used as qubits in quantum computers and as components in quantum sensors. In Infleqtion’s neutral atom quantum systems, rubidium atoms are arranged alongside cesium (Cs) atoms. The two species can interact through Rydberg–Rydberg interactions, enabling entangling gates and quantum-nondemolition (QND) measurements. Read the research.

In this experiment, Infleqtion demonstrated an interspecies Rydberg controlled-ZZZ gate between ⁸⁷Rb and ¹³³Cs atoms with a fidelity of 0.975 ± 0.002. The use of two atomic species also supports independent readout of ancilla and data qubits, which is useful for quantum error correction.