Curator's Take
AI Commentary
This article demonstrates that trapped‑ion qubits can be sympathetically cooled with ions of the same species using only microwave pulses, eliminating the need for a second coolant ion and its dedicated laser system. By achieving near‑ground‑state cooling (average phonon number ≈0.16) while inducing an error below 2 × 10⁻⁴ per cycle, the work shows that hardware overhead can be dramatically reduced without sacrificing fidelity—a key hurdle for scaling ion‑based processors. The approach dovetails with recent moves toward microwave‑driven gates and integrated control electronics, suggesting a more compact and scalable architecture for future quantum computers.
— Mark Eatherly
Summary
Sympathetic cooling of data qubits by coolant ions is an essential technique for trapped-ion quantum computing. Conventionally a second ion species is used, requiring additional lasers and complicating optical setups. We propose a scheme for sympathetic cooling using the same species and test it for $^{43}$Ca$^+$ ions. Pulsed sideband cooling and ion addressing are implemented via integrated microwave control, further simplifying optical requirements. We cool a two-ion gate mode close to its ground state ($\bar{n}\approx 0.16$) and benchmark an induced error on the data qubit of $1.7(4)\times 10^{-4}$ per cooling cycle.