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

TL;DR

This paper introduces a pulse-level scheduling algorithm for neutral-atom quantum devices that optimizes resource utilization and reduces execution time by enabling simultaneous gate operations, especially effective for circuits with fewer qubits.

Contribution

The paper presents a novel pulse-level scheduling algorithm leveraging absorption, achieving optimal resource use and improved execution time over traditional gate-level scheduling.

Findings

The algorithm achieves optimal resource utilization for practical quantum circuits.

Pulse-level scheduling reduces execution time proportionally to circuit depth.

Most beneficial for quantum circuits with fewer qubits.

Abstract

We show how a pulse-level implementation of the multi-qubit gates in neutral-atom device architectures allows for the simultaneous execution of single- and multi-qubit 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 device with a single channel for single- and multi-qubit 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.