HALO: A Fine-Grained Resource Sharing Quantum Operating System

TL;DR

HALO is a quantum operating system that enables fine-grained resource sharing, significantly improving hardware utilization and throughput while maintaining fidelity, addressing the challenge of efficient quantum resource management in cloud environments.

Contribution

HALO introduces a hardware-aware qubit-sharing algorithm and a shot-adaptive scheduler, pioneering fine-grained resource sharing in quantum operating systems.

Findings

Up to 2.44x better hardware utilization

4.44x increased throughput

Fidelity loss within 33%

Abstract

As quantum computing enters the cloud era, thousands of users must share access to a small number of quantum processors. Users need to wait minutes to days to start their jobs, which only takes a few seconds for execution. Current quantum cloud platforms employ a fair-share scheduler, as there is no way to multiplex a quantum computer among multiple programs at the same time, leaving many qubits idle and significantly under-utilizing the hardware. This imbalance between high user demand and scarce quantum resources has become a key barrier to scalable and cost-effective quantum computing. We present HALO, the first quantum operating system design that supports fine-grained resource-sharing. HALO introduces two complementary mechanisms. First, a hardware-aware qubit-sharing algorithm that places shared helper qubits on regions of the quantum computer that minimize routing overhead and avoid cross-talk noise between different users' processes. Second, a shot-adaptive scheduler that allocates execution windows according to each job's sampling requirements, improving throughput and reducing latency. Together, these mechanisms transform the way quantum hardware is scheduled and achieve more fine-grained parallelism. We evaluate HALO on the IBM Torino quantum computer on helper qubit intense benchmarks. Compared to state-of-the-art systems such as HyperQ, HALO improves overall hardware utilization by up to 2.44x, increasing throughput by 4.44x, and maintains fidelity loss within 33%, demonstrating the practicality of resource-sharing in quantum computing.