Work

Quantum Weakest Preconditions for Reasoning about Expected Runtimes of Quantum Programs

Year: 2025

Type: article

Abstract: We study expected runtimes for quantum programs. Inspired by recent work on probabilistic programs, we first define expected runtime as a generalisation of quantum weakest precondition . Then, we show that the expected runtime of a quantum program should be represented as the expectation of an observable (in physics). A method for computing the expected runtimes of quantum programs in finite-dimensional state spaces is developed. Several examples are provided as applications of this method, including computing the expected runtime of quantum Bernoulli Factory – a quantum algorithm for generating random numbers. In particular, using our new method, an open problem of computing the expected runtime of quantum random walks introduced by Ambainis et al. ( STOC 2001) is solved.

Source: Journal of the ACM

DOI: 10.1145/3734516

Authors: Junyi Liu, Li Zhou, Gilles Barthe, Mingsheng Ying

Institutions: Chinese Academy of Sciences, Institute of Software, Madrid Institute for Advanced Studies, IMDEA Software Institute, Tsinghua University

Language: English

Topic: Quantum Computing Algorithms and Architecture

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: bronze

Funder: National Natural Science Foundation of China

Award: 量子程序设计的理论基础