In this article we present an ongoing effort to formalise quantum algorithms and results in quantum information theory using the proof assistant Isabelle/HOL. Formal methods being critical for the safety and security of algorithms and protocols, we foresee their widespread use for quantum computing in the future. We have developed a large library for quantum computing in Isabelle based on a matrix representation for quantum circuits, successfully formalising the no-cloning theorem, quantum teleportation, Deutsch's algorithm, the Deutsch-Jozsa algorithm and the quantum Prisoner's Dilemma. We discuss the design choices made and report on an outcome of our work in the field of quantum game theory.
In this article we present an ongoing effort to formalise quantum algorithms and results in quantum information theory using the proof assistant Isabelle/HOL. Formal methods being critical for the safety and security of algorithms and protocols, we foresee their widespread use for quantum computing in the future. We have developed a large library for quantum computing in Isabelle based on a matrix representation for quantum circuits, successfully formalising the no-cloning theorem, quantum teleportation, Deutsch's algorithm, the Deutsch-Jozsa algorithm and the quantum Prisoner's Dilemma. We discuss the design choices made and report on an outcome of our work in the field of quantum game theory.
Quantum Information Processing, which is an exciting area of research at the intersection of physics and computer science, has great potential for influencing the future development of information processing systems. The building of practical, general purpose Quantum Computers may be some years into the future. However, Quantum Communication and Quantum Cryptography are well developed. Commercial Quantum Key Distribution systems are easily available and several QKD networks have been built in various parts of the world. The security of the protocols used in these implementations rely on information-theoretic proofs, which may or may not reflect actual system behaviour. Moreover, testing of implementations cannot guarantee the absence of bugs and errors. This paper presents a novel framework for modelling and verifying quantum protocols and their implementations using the proof assistant Coq. We provide a Coq library for quantum bits (qubits), quantum gates, and quantum measurement. As a step towards verifying practical quantum communication and security protocols such as Quantum Key Distribution, we support multiple qubits, communication and entanglement. We illustrate these concepts by modelling the Quantum Teleportation Protocol, which communicates the state of an unknown quantum bit using only a classical channel.
We formalize the theory of quantum Hoare logic (QHL) [TOPLAS 33(6),19], an extension of Hoare logic for reasoning about quantum programs. In particular, we formalize the syntax and semantics of quantum programs in Isabelle/HOL, write down the rules of quantum Hoare logic, and verify the soundness and completeness of the deduction system for partial correctness of quantum programs. As preliminary work, we formalize some necessary mathematical background in linear algebra, and define tensor products of vectors and matrices on quantum variables. As an application, we verify the correctness of Grover’s search algorithm. To our best knowledge, this is the first time a Hoare logic for quantum programs is formalized in an interactive theorem prover, and used to verify the correctness of a nontrivial quantum algorithm.
Quantum Hoare Logic (QHL) was introduced in Ying's work to specify and reason about quantum programs. In this paper, we implement a theorem prover for QHL based on Isabelle/HOL. By applying the theorem prover, verifying a quantum program against a specification is transformed equivalently into an order relation between matrices. Due to the limitation of Isabelle/HOL, the calculation of the order relation is solved by calling an outside oracle written in Python. To the best of our knowledge, this is the first theorem prover for quantum programs. To demonstrate its power, the correctness of two well-known quantum algorithms, i.e., Grover Quantum Search and Quantum Phase Estimation (the key step in Shor's quantum algorithm of factoring in polynomial time) are proved using the theorem prover. These are the first mechanized proofs for both of them.
Research in contemporary physics is emphasizing the development and evolution of computer systems to facilitate the calculations. Quantum computing is a branch of modern physics is believed promising results for the future, Thanks to the ability of qubits to store more information than a bit. The work of this paper focuses on the simulation of certain quantum algorithms such as the prisoner's dilemma in its quantum version using the MATHEMATICA® software and implementing stochastic version of the software MAPLE ® and the Grover search algorithm that simulates finding a needle in a haystack.
This book, Quantum Computing: Algorithms, Architectures and Applications, has been carefully developed as a comprehensive resource to navigate the dynamic and complex world of quantum technologies. Intended for students, researchers, engineers, and technology enthusiasts, it aims to connect fundamental concepts with real-world implementation. The journey begins with the core principles of quantum mechanics relevant to computing, laying the groundwork that differentiates quantum systems from classical approaches. It further explores quantum gates, circuits, and computational logic, along with key topics such as error correction, system architectures, entanglement, superposition, and the no-cloning theorem. As the discussion progresses, the book examines foundational quantum algorithms, including the Deutsch–Jozsa algorithm, Simon’s problem, and others. These sections not only explain technical concepts but also encourage readers to rethink computational possibilities and limitations. The book also highlights practical applications and industry adoption. Quantum computing is increasingly influencing fields such as cryptography, finance, drug discovery, and climate science. Through global and regional case studies, readers gain insight into how various sectors are embracing this technological shift. A clear and structured approach has been maintained throughout, making the content accessible to beginners while still valuable for experienced professionals. The aim is to balance depth with clarity, ensuring both rigor and ease of understanding. While quantum computing continues to evolve with ongoing advancements and discoveries, the driving forces behind its progress remain curiosity, innovation, and collaboration.
The verification of quantum computing algorithms presents a significant hurdle due to the probabilistic nature of quantum mechanics and the complex entanglement inherent in quantum computations. This paper proposes a novel approach to address this challenge by developing a formal language and a corresponding verification tool tailored explicitly for quantum algorithm specification and verification. The system leverages concepts from quantum information theory and formal methods to provide a rigorous framework for ensuring the correctness of quantum algorithms. We introduce a new formalism that allows for precise description of quantum circuits and their operations, combined with automated theorem proving techniques to systematically verify the algorithm's behavior against a given specification. The key innovation lies in the ability to reason about quantum states and measurements within a formal setting, enabling a more comprehensive understanding and validation of these algorithms. This work lays the foundation for increased confidence in the development and deployment of quantum computing technologies.