Trapped-ion two-qubit gates with >99.99% fidelity without ground-state cooling

Introduces a smooth-detuning trapped-ion entangling gate that adiabatically suppresses residual spin-motion entanglement and operates without motional ground-state cooling.

Key Results

• Estimated two-qubit gate error: $8.4(7)\times 10^{-5}$, corresponding to $99.9916(7)\%$ fidelity.
• Total smooth-gate duration in the benchmark: $225.8\mu \mathrm{s}$.
• Error remained $\lesssim 5\times 10^{-4}$ at mean phonon occupation up to $\bar{n}=9.4(3)$.

Links

• arXiv: 2510.17286

Zoo Links

• trapped-ion-qubit
• molmer-sorenson-gate
• quantum-gate