Pulse-Level Scheduling of Quantum Circuits for Neutral-Atom Devices

Abstract

We show how a pulse-level implementation of certain multiqubit gates allows for the simultaneous execution of single- and multiqubit gates acting on overlapping sets of qubits, in a mechanism we name absorption. With absorption as a foundation, we present an algorithm to schedule the execution of a quantum circuit as a pulse sequence on a neutral-atom quantum processor with a single channel for single- and multiqubit gate execution. For any quantum circuit of practical relevance, we observe that the algorithm results in an optimal utilization of the available resources that cannot be surpassed by a different scheduling strategy. Our benchmarks against a custom scheduler attempting to maximize parallelization at the gate level show the time gained by the pulse-level scheduler is proportional to the depth and is most pronounced for quantum circuits with fewer qubits. We finally illustrate how the concept of absorption can also be used in other architectures.