The Quantum software lifecycle

Abstract

With recent advances in the development of more powerful quantum computers, the research area of quantum software engineering is emerging, having the goal to provide concepts, principles, and guidelines to develop high-quality quantum applications. In classical software engineering, lifecycles are used to document the process of designing, implementing, maintaining, analyzing, and adapting software. Such lifecycles provide a common understanding of how to develop and operate an application, which is especially important due to the interdisciplinary nature of quantum computing. Since today's quantum applications are, in most cases, hybrid, consisting of quantum and classical programs, the lifecycle for quantum applications must involve the development of both kinds of programs. However, the existing lifecycles only target the development of quantum or classical programs in isolation. Additionally, the various programs must be orchestrated, e.g., using workflows. Thus, the development of quantum applications also incorporates the workflow lifecycle. In this chapter, we analyze the software artifacts usually comprising a quantum application and present their corresponding lifecycles. Furthermore, we identify the points of connection between the various lifecycles and integrate them into the overall quantum software development lifecycle. Therefore, the integrated lifecycle serves as a basis for the development and execution of hybrid quantum applications.

Automated Quantum Hardware Selection for Quantum Workflows

“…A universal quantum circuit consists of a set of gates and measurements operating on different qubits [3]. However, computations on today's quantum computers are affected by various kinds of noise, such as gate-errors, qubit decoherence, or readout-errors [8,17]. This noise leads to errors in computations and restricts the maximum circuit depth of the executable quantum circuits [11].…”

“…The execution of quantum algorithms typically includes classical pre-and postprocessing tasks before and after executing the corresponding quantum circuits [8,17]. For example, the generation of an initialization circuit to prepare the initial state in the register of the quantum hardware depending on the input data [34].…”

“…In addition to the execution of quantum circuits, quantum algorithms often require algorithm-specific pre-or post-processing tasks, e.g., Shor's [12] or Simon's algorithm [15]. Furthermore, there may be algorithm-independent tasks, such as mitigating readouterrors after the execution of a quantum circuit [8,16,17]. Thus, workflows can be used to orchestrate these tasks to benefit from their advantages, such as scalability, reliability, robustness, and comprehensive error handling mechanisms [18][19][20].…”

“…Thereby, QuantME provides modeling constructs for the different frequently occurring tasks abstracting from the underlying technical details. However, the various pre-processing, quantum circuit execution, and post-processing tasks are implemented differently, depending on the quantum hardware to use [14,17]. For example, because an SDK enabling the execution on this quantum hardware must be utilized [10].…”

QProv: A provenance system for quantum computing

“…In recent years, various quantum hardware providers, such as IBM, Rigetti, or IonQ, developed quantum computers and provided access to them via the cloud [1,7]. Therefore, quantum computers have become accessible to the public, and use cases from various application areas can now be implemented, tested, and executed on real quantum computers [3,8,9]. However, today's quantum computers are affected by noise from various sources, which can cause errors in computations [1,5,8].…”