Neutral atom arrays have become a promising platform for quantum computing, especially the field programmable qubit array (FPQA) endowed with the unique capability of atom movement. This feature allows dynamic alterations in qubit connectivity during runtime, which can reduce the cost of executing long-range gates and improve parallelism. However, this added flexibility introduces new challenges in circuit compilation. Inspired by the placement and routing strategies for FPGAs, we propose to map all data qubits to fixed atoms while utilizing movable atoms to route for 2-qubit gates between data qubits. Coined flying ancillas, these mobile atoms function as ancilla qubits, dynamically generated and recycled during execution. We present Q-Pilot, a scalable compiler for FPQA employing flying ancillas to maximize circuit parallelism. For two important quantum applications, quantum simulation and the Quantum Approximate Optimization Algorithm (QAOA), we devise domain-specific routing strategies. In comparison to alternative technologies such as superconducting devices or fixed atom arrays, Q-Pilot effectively harnesses the flexibility of FPQA, achieving reductions of 1.4x, 27.7x, and 6.3x in circuit depth for 100-qubit random, quantum simulation, and QAOA circuits, respectively.
@inproceedings{wang2024qpilot,
title={Q-Pilot: Field Programmable Qubit Array Compilation with Flying Ancillas},
author={Wang, Hanrui and Tan, Bochen and Liu, Pengyu and Liu, Yilian and Gu, Jiaqi and Cong, Jason and Han, Song},
booktitle={Proceedings of the 61th ACM/IEEE Design Automation Conference},
pages={1--6},
year={2024}}
This work is partially supported by NSF grant 442511-CJ-22291, MITIBM Watson AI Lab, and Qualcomm Innovation Fellowship. The authors would like to thank Dolev Bluvstein, Mikhail D. Lukin, and Hengyun Zhou for valuable discussions on neutral atom arrays.
