Quantum computing, a data processing technology based on quantum mechanics, is one of the most promising technologies in the current research scenario. Indeed, this new paradigm disrupts how information is conceived, stored, and processed thus making quantum computers still complicated to manage and program. Added to this complexity is the need to guarantee quantum coherence, which could fail due to either noise or the influence of external parameters. While high-power quantum computers are usually conditioned and protected by complex and expensive systems supplied by the manufacturer itself, relatively low-cost desk quantum computers are only accompanied by data sheets reporting operation limits within influence parameters should be constrained but no analytical information is provided about computer sensitivity to the parameters. In this paper, the authors report the experimental results of a desk two-qubit quantum computer performance characterization carried out by evaluating its sensitivity to influence parameters during the execution of elementary algorithms. The aim is to help face the use of this frontier computing resource also in research projects where funds cannot cover the cost of complex conditioning systems. After a brief introduction on quantum computing and circuits, the adopted test method is described, and the experimental results discussed in detail.
Quantum computing, a data processing technology based on quantum mechanics, is one of the most promising technologies in the current research scenario. Indeed, this new paradigm disrupts how information is conceived, stored, and processed thus making quantum computers still complicated to manage and program. Added to this complexity is the need to guarantee quantum coherence, which could fail due to either noise or the influence of external parameters. While high-power quantum computers are usually conditioned and protected by complex and expensive systems supplied by the manufacturer itself, relatively low-cost desk quantum computers are only accompanied by data sheets reporting operation limits within influence parameters should be constrained but no analytical information is provided about computer sensitivity to the parameters. In this paper, the authors report the experimental results of a desk two-qubit quantum computer performance characterization carried out by evaluating its sensitivity to influence parameters during the execution of elementary algorithms. The aim is to help face the use of this frontier computing resource also in research projects where funds cannot cover the cost of complex conditioning systems. After a brief introduction on quantum computing and circuits, the adopted test method is described, and the experimental results discussed in detail.
Quantum computing has emerged as a promising paradigm for addressing computational challenges in physics that remain intractable for classical methods. This study presents a quantitative benchmarking analysis of prominent quantum algorithms applied to representative physics problem classes, with the objective of evaluating their computational performance relative to state-of-the-art classical algorithms. Using standardized performance metrics—including execution time, algorithmic complexity, resource utilization, accuracy, scalability, and quantum advantage ratios—the study systematically compares quantum and classical approaches across multiple experimental configurations. The results demonstrate that quantum algorithms exhibit measurable performance gains for specific problem types, particularly in terms of runtime efficiency and scaling behavior, while also highlighting practical constraints related to qubit requirements and circuit depth. Visual and tabulated analyses further reveal that quantum advantage is highly problem-dependent and influenced by algorithmic structure and system size. Overall, the findings provide empirical evidence that quantum algorithms can offer substantial computational benefits for selected physics applications, while underscoring the importance of quantitative benchmarking in distinguishing theoretical promise from practical performance. This work contributes to ongoing efforts to objectively assess quantum advantage and informs future research directions in quantum algorithm development and physics-based applications.
Purpose: The aim of the study was to assess the influence of quantum computing algorithms on molecular simulations in material science in Pakistan. Materials and Methods: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: The study found that traditional classical computing methods often struggle with the complex and large-scale calculations required to simulate molecular interactions and properties, leading to approximations that can limit the precision of predictions. Quantum algorithms, particularly those based on quantum annealing and variational quantum eigensolver (VQE), offer the ability to process vast amounts of data simultaneously, making them highly effective for solving problems involving quantum states of matter. Studies have demonstrated that quantum computing can achieve a higher degree of accuracy in predicting molecular structures, reaction mechanisms, and material properties compared to classical approaches. Additionally, quantum computing can significantly reduce the time required for these simulations, thereby accelerating the development of new materials and technologies. Implications to Theory, Practice and Policy: Computational complexity theory, quantum information theory and algorithmic information theory may be used to anchor future studies on assessing the influence of quantum computing algorithms on molecular simulations in material science in Pakistan. In the realm of practical applications, the development of robust quantum computing infrastructure is essential for realizing the full potential of quantum algorithms in molecular simulations. Policymakers have a crucial role in supporting the research and development of quantum computing technologies, particularly in their application to material science.
Quantum computing promises revolutionary advancements across various fields, yet its realization hinges critically on the reliability of its hardware. Unlike classical computing, quantum systems are exceptionally sensitive to environmental noise and prone to errors, leading to significant challenges in maintaining coherence and accurate computation. This research presents a formal model designed to rigorously analyze the reliability of quantum computing hardware. The model incorporates probabilistic representations of quantum gates and qubits, alongside noise models that capture various sources of error, and evaluates the effectiveness of fault-tolerance techniques. The core of the model is a simulation framework allowing for comprehensive evaluation of the impact of these factors on the overall system performance. This approach provides a quantitative basis for designing more robust quantum computing systems and optimizing operational strategies, moving beyond intuitive estimations and towards a scientifically grounded understanding of quantum hardware reliability. The model is presented with detailed formulas and mathematical notations, offering a precise and verifiable framework for analysis.
In the context of rapid technological advancements, progress in chip manufacturing technology is propelling electronic devices toward miniaturization and high efficiency at an unprecedented pace. The fundamental principles of quantum mechanics are beginning to play a crucial role in modern electronic devices, providing the foundation for new technological methods and research directions. Optical quantum signal processing, as an important branch of quantum technology, utilizes the quantum properties of photons for information processing and transmission, offering advantages such as high bandwidth, low noise, and strong resistance to interference. However, current optical quantum measurement and control instruments face significant challenges in terms of real-time performance and programming complexity, resulting in reduced data processing efficiency and significantly increased development costs. This study implements a real-time processing algorithm for optical quantum signals on a Field-Programmable Gate Array (FPGA). The algorithm possesses advantages of real-time performance, low power consumption, and high integration. It allows for rapid functionality switching and efficient optical quantum signal processing. The design specifically aims to enhance the signal-to-noise ratio, significantly improving measurement accuracy and reliability. Experimental results indicate that this method substantially enhances the measurement precision and signal-to-noise ratio of optical quantum signals. This research provides an efficient and reliable new method for optical quantum signal processing, laying a solid foundation for further studies in quantum communication, quantum computing, and quantum precision measurement.
Quantum computing is an emerging technology that has the potential to change the perspectives and applications of computing in general. A wide range of applications are enabled: from faster algorithmic solutions of classically still difficult problems to theoretically more secure communication protocols. A quantum computer uses the quantum mechanical effects of particles or particle-like systems, and a major similarity between quantum and classical computers consists of both being abstracted as information processing machines. Whereas a classical computer operates on classical digital information, the quantum computer processes quantum information, which shares similarities with analog signals. One of the central differences between the two types of information is that classical information is more fault-tolerant when compared to its quantum counterpart. Faults are the result of the quantum systems being interfered by external noise, but during the last decades quantum error correction codes (QECC) were proposed as methods to reduce the effect of noise. Reliable quantum circuits are the result of designing circuits that operate directly on encoded quantum information, but the circuit’s reliability is also increased by supplemental redundancies, such as sub-circuit repetitions. Reliable quantum circuits have not been widely used, and one of the major obstacles is their vast associated resource overhead, but recent quantum computing architectures show promising scalabilities. Consequently the number of particles used for computing can be more easily increased, and that the classical control hardware (inherent for quantum computation) is also more reliable. Reliable quantum circuits haev been investigated for almost as long as general quantum computing, but their limited adoption (until recently) has not generated enough interest into their systematic design. The continuously increasing practical relevance of reliability motivates the present thesis to investigate some of the first answers to questions related to the background and the methods forming a reliable quantum circuit design stack. The specifics of quantum circuits are analysed from two perspectives: their probabilistic behaviour and their topological properties when a particular class of QECCs are used. The quantum phenomena, such as entanglement and superposition, are the computational resources used for designing quantum circuits. The discrete nature of classical information is missing for quantum information. An arbitrary quantum system can be in an infinite number of states, which are linear combinations of an exponential number of basis states. Any nontrivial linear combination of more than one basis states is called a state superposition. The effect of superpositions becomes evident when the state of the system is inferred (measured), as measurements are probabilistic with respect to their output: a nontrivial state superposition will collapse to one of the component basis states, and the measurement result is known exactly only after the measurement. A quantum system is, in general, composed from identical subsystems, meaning that a quantum computer (the complete system) operates on multiple similar particles (subsystems). Entanglement expresses the impossibility of separating the state of the subsystems from the state of the complete system: the nontrivial interactions between the subsystems result into a single indivisible state. Entanglement is an additional source of probabilistic behaviour: by measuring the state of a subsystem, the states of the unmeasured subsystems will probabilistically collapse to states from a well defined set of possible states. Superposition and entanglement are the building blocks of quantum information teleportation protocols, which in turn are used in state-of-the-art fault-tolerant quantum computing architectures. Information teleportation implies that the state of a subsystem is moved to a second subsystem without copying any information during the process. The probabilistic approach towards the design of quantum circuits is initiated by the extension of classical test and diagnosis methods. Quantum circuits are modelled similarly to classical circuits by defining gate-lists, and missing quantum gates are modelled by the single missing gate fault. The probabilistic approaches towards quantum circuits are facilitated by comparing these to stochastic circuits, which are a particular type of classical digital circuits. Stochastic circuits can be considered an emulation of analogue computing using digital components. A first proposed design method, based on the direct comparison, is the simulation of quantum circuits using stochastic circuits by mapping each quantum gate to a stochastic computing sub-circuit. The resulting stochastic circuit is compiled and simulated on FPGAs. The obtained results are encouraging and illustrate the capabilities of the proposed simulation technique. However, the exponential number of possible quantum basis states was translated into an exponential number of stochastic computing elements. A second contribution of the thesis is the proposal of test and diagnosis methods for both stochastic and quantum circuits. Existing verification (tomographic) methods of quantum circuits were targeting the reconstruction of the gate-lists. The repeated execution of the quantum circuit was followed by different but specific measurement at the circuit outputs. The similarities between stochastic and quantum circuits motivated the proposal of test and diagnosis methods that use a restricted set of measurement types, which minimise the number of circuit executions. The obtained simulation results show that the proposed validation methods improve the feasibility of quantum circuit tomography for small and medium size circuits. A third contribution of the thesis is the algorithmic formalisation of a problem encountered in teleportation-based quantum computing architectures. The teleportation results are probabilistic and require corrections represented as quantum gates from a particular set. However, there are known commutation properties of these gates with the gates used in the circuit. The corrections are not applied as dynamic gate insertions (during the circuit’s execution) into the gate-lists, but their effect is tracked through the circuit, and the corrections are applied only at circuit outputs. The simulation results show that the algorithmic solution is applicable for very large quantum circuits. Topological quantum computing (TQC) is based on a class of fault-tolerant quantum circuits that use the surface code as the underlying QECC. Quantum information is encoded in lattice-like structures and error protection is enabled by the topological properties of the lattice. The 3D structure of the lattice allows TQC computations to be visualised similarly to knot diagrams. Logical information is abstracted as strands and strand interactions (braids) represent logical quantum gates. Therefore, TQC circuits are abstracted using a geometrical description, which allows circuit input-output transformations (correlations) to be represented as geometric sub-structures. TQC design methods were not investigated prior to this work, and the thesis introduces the topological computational model by first analysing the necessary concepts. The proposed TQC design stack follows a top-down approach: an arbitrary quantum circuit is decomposed into the TQC supported gate set; the resulting circuit is mapped to a lattice of appropriate dimensions; relevant resulting topological properties are extracted and expressed using graphs and Boolean formulas. Both circuit representations are novel and applicable to TQC circuit synthesis and validation. Moreover, the Boolean formalism is broadened into a formal mechanism for proving circuit correctness. The thesis introduces TQC circuit synthesis, which is based on a novel logical gate geometric description, whose formal correctness is demonstrated. Two synthesis methods are designed, and both use a general planar representation of the circuit. Initial simulation results demonstrate the practicality and performance of the methods. An additional group of proposed design methods solves the problem of automatic correlation construction. The methods use validity criteria which were introduced and analysed beforehand in the thesis. Input-output correlations existing in the circuit are inferred using both the graph and the Boolean representation. The thesis extends the TQC state-of-the-art by recognising the importance of correlations in the validation process: correlation construction is used as a sub-routine for TQC circuit validation. The presented cross-layer validation procedure is useful when investigating both the QECC and the circuit, while a second proposed method is QECC-independent. Both methods are scalable and applicable even to very large circuits. The thesis completes with the analysis of TQC circuit identities, where the developed Boolean formalism is used. The proofs of former known circuit identities were either missing or complex, and the presented approach reduces the length of the proofs and represents a first step towards standardising them. A new identity is developed and detailed during the process of illustrating the known circuit identities. Reliable quantum circuits are a necessity for quantum computing to become reality, and specialised design methods are required to support the quest for scalable quantum computers. This thesis used a twofold approach towards this target: firstly by focusing on the probabilistic behaviour of quantum circuits, and secondly by considering the requirements of a promising quantum computing architecture, namely TQC. Both approaches resulted in a set of design methods enabling the investigation of reliable quantum circuits. The thesis contributes with the proposal of a new quantum simulation technique, no
Purpose: This study investigates the effects of quantum mechanical properties of complex systems on advanced technological applications in Japan. Materials and Methods: The study adopted a desktop methodology. Desk research refers to secondary data or that which can be collected without fieldwork. Desk research is basically involved in collecting data from existing resources hence it is often considered a low-cost technique as compared to field research, as the main cost is involved in executive’s time, telephone charges and directories. Thus, the study relied on already published studies, reports and statistics. This secondary data was easily accessed through the online journals and library. Results: The literature review and research findings highlight the significant effects of quantum mechanical properties of complex systems on various technological applications in Japan. The study reveals that quantum entanglement, quantum coherence, and quantum interference can be exploited for quantum computing, quantum communication, quantum sensing, quantum cryptography, quantum metrology, and other advanced technologies. The study also discusses the challenges and limitations of utilizing quantum mechanical properties in technological applications, such as decoherence, environmental interactions, and technical feasibility. Recommendations: This study offers a unique contribution to understanding the effects of quantum mechanical properties of complex systems on advanced technological applications in Japan. The research advances the knowledge in the field of quantum information science, quantum technology, and interdisciplinary research between quantum mechanics and technology. The findings provide insights into the potential applications of quantum mechanical properties in various technological fields, and their implications for theory, practice, and policy. The study has practical implications for researchers, engineers, policymakers, and industries involved in quantum technology research and development in Japan and beyond, guiding the future direction of quantum technology innovation and policy formulation