Amplitude-noise-resilient entangling gates for trapped ions

Noise resilience of quantum information processing is a crucial precondition to reach the fault-tolerance threshold. While resilience to many types of noise can be achieved through suitable control schemes, resilience to amplitude noise seems to be elusive within the common harmonic approximation for the bus mode of trapped ions. We show that weak anharmonicities admit control schemes that achieve amplitude-noise resilience consistent with state-of-the-art experimental requirements and that the required anharmonicities can be achieved with current standards of microstructured traps or even the intrinsically anharmonic Coulomb interaction. This approach applies broadly to any platform that employs a bosonic bus as a qubit coupler.