Suppressing crosstalk for Rydberg quantum gates

Scientists have introduced a technique for reducing crosstalk in the implementation of controlled-Z gates on neutral atom quantum computers that use local laser addressing. A fraction of the light applied to target atoms typically reaches neighboring atoms, leading to errors in the quantum operations. The analysis focused on a configuration with two atoms undergoing the gate and a third atom affected by the leaked light. Through perturbative methods, the team constructed a gate protocol modeled on spin-echo techniques. This design eliminates the primary contribution to amplitude errors that arise from the crosstalk. Numerical simulations of the protocol show an improvement in gate fidelity by two orders of magnitude. The enhancement holds across many parameter values typical of current experimental setups. To address any leftover phase errors, the researchers also created a compensating circuit. The work demonstrates that the protocol can suppress the leading order amplitude error. Results indicate that local addressing can support high-fidelity quantum gates on Rydberg-based quantum computers.