NetQIR: An Extension of QIR for Distributed Quantum Computing

TL;DR

NetQIR extends Microsoft's QIR to better support distributed quantum computing by adding network communication instructions, enabling scalable and modular quantum software development across multiple quantum processors.

Contribution

It introduces a novel extension of QIR tailored for distributed quantum computing, addressing the lack of abstraction at network and hardware layers.

Findings

Defines network communication instructions independent of hardware

Supports compiler development for distributed quantum algorithms

Bridges high-level algorithms with low-level hardware execution

Abstract

The rapid advancement of quantum computing has highlighted the need for scalable and efficient software infrastructures to fully exploit its potential. Current quantum processors face significant scalability constraints due to the limited number of qubits per chip. In response, distributed quantum computing (DQC) -- achieved by networking multiple quantum processor units (QPUs) -- is emerging as a promising solution. To support this paradigm, robust intermediate representations (IRs) are needed to translate high-level quantum algorithms into executable instructions suitable for distributed systems. This paper presents NetQIR, an extension of Microsoft's Quantum Intermediate Representation (QIR), specifically designed to facilitate DQC by incorporating new instruction specifications. NetQIR was developed in response to the lack of abstraction at the network and hardware layers identified in the existing literature as a significant obstacle to effectively implementing distributed quantum algorithms. Based on this analysis, NetQIR introduces new essential abstraction features to support compilers in DQC contexts. It defines network communication instructions independent of specific hardware, abstracting the complexities of inter-QPU communication. Leveraging the QIR framework, NetQIR aims to bridge the gap between high-level quantum algorithm design and low-level hardware execution, thus promoting modular and scalable approaches to quantum software infrastructures for distributed applications.