When Abstraction Breaks Physics: Rethinking Modular Design in Quantum Software
Jianjun Zhao
TL;DR
This paper argues that classical abstraction mechanisms are often incompatible with quantum semantics, risking violations of unitarity, entanglement locality, and measurement semantics in quantum software. It analyzes three failure modes of naive abstraction and derives design principles to preserve quantum correctness across modular boundaries. The authors propose research directions including quantum-specific type and effect systems, contract-based module design, and abstraction-aware tooling to enforce physically valid abstractions. The work aims to provide a foundation for scalable, reliable quantum software engineering by integrating quantum physics into abstraction and modularity practices.
Abstract
Abstraction is a fundamental principle in classical software engineering, which enables modularity, reusability, and scalability. However, quantum programs adhere to fundamentally different semantics, such as unitarity, entanglement, the no-cloning theorem, and the destructive nature of measurement, which introduce challenges to the safe use of classical abstraction mechanisms. This paper identifies a fundamental conflict in quantum software engineering: abstraction practices that are syntactically valid may violate the physical constraints of quantum computation. We present three classes of failure cases where naive abstraction breaks quantum semantics and propose a set of design principles for physically sound abstraction mechanisms. We further propose research directions, including quantum-specific type systems, effect annotations, and contract-based module design. Our goal is to initiate a systematic rethinking of abstraction in quantum software engineering, based on quantum semantics and considering engineering scalability.