Spontaneous Raman scattering out of a metastable atomic qubit

Abstract

Metastable qubits in atomic systems can enable large-scale quantum computing by simplifying hardware requirements and adding efficient erasure conversion to the pre-existing toolbox of high-fidelity laser-based control. For trapped atomic ions, the fundamental error floor of this control is given by spontaneous Raman and Rayleigh scattering from short-lived excited states. We measure spontaneous Raman scattering rates out of a metastable $D_{5/2}$ qubit manifold of a single trapped ${}^{40}$Ca${}^{+}$ ion illuminated by 976 nm light that is -44 THz detuned from the dipole-allowed transition to the $P_{3/2}$ manifold. This supports the calculation of error rates from both types of scattering during one- and two-qubit gates on this platform, thus demonstrating that infidelities $<10^{-4}$ are possible.

6 pages, 4 figures

References in corpus (5)

• Errors in trapped-ion quantum gates due to spontaneous photon scattering
• Fast Quantum State Control of a Single Trapped Neutral Atom
• Quantum Gates with Phase Stability over Space and Time
• Combining experiments and relativistic theory for establishing accurate radiative quantities in atoms: the lifetime of the ${}^2$P${}_{3/2}$ state in ${}^{40}$Ca${}^{+}$
• Experimental realization of direct entangling gates between dual-type qubits