This paper describes software for transformation of XML-based description of quantum circuits into graphical representation. It uses Quantum Markup Language introduced in [8] and produces Scalable Vector Graphics (SVG) representation of data. Because XML is a popular data format supported by many programming languages, presented converter does not depend on simulation environment and can be easily connected with existing software for simulation of quantum computing. Problems with visualisation of quantum circuit description point out some limitations of quantum circuits model in practical application e.g. quantum programing languages.
This paper describes software for transformation of XML-based description of quantum circuits into graphical representation. It uses Quantum Markup Language introduced in [8] and produces Scalable Vector Graphics (SVG) representation of data. Because XML is a popular data format supported by many programming languages, presented converter does not depend on simulation environment and can be easily connected with existing software for simulation of quantum computing. Problems with visualisation of quantum circuit description point out some limitations of quantum circuits model in practical application e.g. quantum programing languages.
This Master thesis examines issues of interoperability and integration between the Classic Information Science (CIS) and Quantum Information Science (QIS). It provides a short introduction to the Extensible Markup Language (XML) and proceeds to describe the development steps that have lead to a prototype XML specification for quantum computing (QIS-XML). QIS-XML is a proposed framework, based on the widely used standard (XML) to describe, visualize, exchange and process quantum gates and quantum circuits. It also provides a potential approach to a generic programming language for quantum computers through the concept of XML driven compilers. Examples are provided for the description of commonly used quantum gates and circuits, accompanied with tools to visualize them in standard web browsers. An algorithmic example is also presented, performing a simple addition operation with quantum circuits and running the program on a quantum computer simulator. Overall, this initial effort demonstrates how XML technologies could be at the core of the architecture for describing and programming quantum computers. By leveraging a widely accepted standard, QIS-XML also builds a bridge between classic and quantum IT, which could foster the acceptance of QIS by the ICT community and facilitate the understanding of quantum technology by IT experts. This would support the consolidation of Classic Information Science and Quantum Information Science into a Complete Information Science, a challenge that could be referred to as the "Information Science Grand Unification Challenge".
While Quantum Information Science (QIS) is still in its infancy, the ability for quantum based hardware or computers to communicate and integrate with their classical counterparts will be a major requirement towards their success. Little attention however has been paid to this aspect of QIS. To manage and exchange information between systems, today's classic Information Technology (IT) commonly uses the eXtensible Markup Language (XML) and its related tools. XML is composed of numerous specifications related to various fields of expertise. No such global specification however has been defined for quantum computers. QIS-XML is a proposed XML metadata specification for the description of fundamental components of QIS (gates & circuits) and a platform for the development of a hardware independent low level pseudo-code for quantum algorithms. This paper lays out the general characteristics of the QIS-XML specification and outlines practical applications through prototype use cases.
Abstract The use of graphical language in quantum computing for the representation of algorithms, although intuitive, is not very useful for different tasks such as the description of quantum circuits in text environments, the calculation of quantum states or the optimization of quantum circuits. While classical circuits can be represented either by circuit graphs or by Boolean expressions, quantum circuits have until now predominantly been illustrated as circuit graphs because no formal language for quantum circuits that allows algebraic manipulations has so far been accepted. This work proposes a means to represent quantum circuits in a convenient and concise manner, similar to the way Boolean expressions are used in classical circuits. The proposed notation allows the consistent and parameterized description of quantum algorithms, as well as the easy handling of the elements that compose it to achieve powerful optimizations in the number of gates of the circuits. To visualize it, a software implementation of an algebraic quantum circuit framework has been made, which allows describing quantum circuits, as well as their respective state vectors, using the proposed algebraic language.
None of the quantum computing applications imagined will ever become a reality without quantum software. Quantum programmes have, to date, been coded with ad hoc techniques. Researchers in the field of quantum software engineering are, therefore, now demanding more systematic techniques and methods with which to produce software with sufficient quality. One of the challenges and lessons learned from classic software engineering is the need for high-level, abstract and technology-independent representations with which to design software before it is coded. This paper specifically addresses this challenge for quantum software design. Since UML is a well-proven modelling language that has been widely employed by industry for some time, we propose a UML extension for the representation of quantum algorithms. Our proposal comprises the definition of a UML profile based on various stereotypes that can be applied to the existing UML activity diagrams in order to represent quantum circuits. The advantage of this representation is that UML quantum circuits can be interrelated with other UML elements and diagrams, which will make it possible to represent various concerns and viewpoints of the so-called hybrid information systems. This will consequently enable classical and quantum aspects to be modelled together in integrated designs in a technological-agnostic manner that is already supported by a considerable number of existing software design tools.
An efficient and intuitive format of quantum programs is an indispensable component to handle large-scale quantum computers. Representing and manipulating a sequence of quantum instructions as a network of quantum gates, i.e., quantum circuits, is one of the most successful approaches. Quantum circuits are intuitive since there are similar representations in classical engineering, such as electric or digital circuits. However, due to their differences from these classical circuits, naively automated manipulation and optimization for quantum circuit networks easily tend to an ill-defined format. To avoid this problem, a flexible and verifiable network format of quantum circuits is strongly demanded. In this extended poster abstract, we propose a representation with these properties, named quantum circuit fragments. In our representation, the connectivity of several types of wires in quantum circuits, qubit, control, and measurement-feedback wiring, are kept as three sets. We also provide a linear time algorithm to validate that our format can be converted to quantum circuits. Using our preliminary software to treat quantum circuit fragments, Q-Divide, we demonstrated that code complexity can be halved in practical cases. Thus, our work improves the efficiency of quantum computer development and motivates further exploration for efficient representation and manipulation of large-scale quantum programs.
Quantum-mechanical phenomena are playing an increasing role in information processing as transistor sizes approach the nanometer level, while the securest forms of communication rely on quantum data encoding. When they involve a finite number of basis states, these phenomena can be modeled as quantum circuits, the quantum analogue of conventional or classical logic circuits. Simulation of quantum circuits can therefore be used as a tool to evaluate issues in the design of quantum information processors. Unfortunately, simulating such phenomena efficiently is exceedingly difficult. The matrices representing quantum operators (gates) and vectors modeling quantum states grow exponentially with the number of quantum bits. The information represented by quantum states and operators often exhibits structure that can be exploited when simulating certain classes of quantum circuits. We study the development of simulation methods that run on classical computers and take advantage of such repetitions and redundancies. In particular, we define a new data structure for simulating quantum circuits called the quantum information decision diagram (QuIDD). A QuIDD is a compressed graph representation of a vector or matrix and permits computations to be performed directly on the compressed data. We develop a comprehensive set of algorithms for operating on QuIDDs in both the state-vector and density-matrix formats, and evaluate their complexity. These algorithms have been implemented in a general-purpose simulator program for quantum-mechanical applications called QuIDDPro. Through extensive experiments conducted on representative quantum simulation applications, including Grover's search algorithm, error characterization, and reversible circuits, we demonstrate that QuIDDPro is faster than other existing quantum-mechanical simulators such as the National Institute of Standards and Technology's QCSim program, and is far more memory-efficient. Using QuIDDPro, we explore the advantages of quantum computation over classical computation, simulate quantum errors and error correction, and study the impact of numerical precision on the fidelity of simulations. We also develop several novel algorithms for testing quantum circuit equivalence and compare them empirically. The QuIDDPro software is equipped with a user-friendly interface and is distributed with numerous example scripts. It has been used as a laboratory supplement for quantum computing courses at several universities.