The articles in this special section focus on quantum computing. After decades of research and development, quantum computing has recently grown into one of the hottest and most promising of all emerging fields. While large-scale quantum computing was just a pipe dream even a decade ago, today there is an intense race around the globe to build a practical quantum computer. So, as a microwave engineer, why should you be interested in quantum computing? It turns out that there is actually a significant amount of microwave engineering involved in the implementation of many controllable quantum systems.
The articles in this special section focus on quantum computing. After decades of research and development, quantum computing has recently grown into one of the hottest and most promising of all emerging fields. While large-scale quantum computing was just a pipe dream even a decade ago, today there is an intense race around the globe to build a practical quantum computer. So, as a microwave engineer, why should you be interested in quantum computing? It turns out that there is actually a significant amount of microwave engineering involved in the implementation of many controllable quantum systems.
During the past decade, quantum computing has grown from a field known mostly for generating scientific papers to one that is poised to reshape computing as we know it [1]. Major industrial research efforts in quantum computing are currently underway at many companies, including IBM [2], Microsoft [3], Google [4], [5], Alibaba [6], and Intel [7], to name a few. The European Union [8], Australia [9], China [10], Japan [11], Canada [12], Russia [13], and the United States [14] are each funding large national research initiatives focused on the quantum information sciences. And, recently, tens of start-up companies have emerged with goals ranging from the development of software for use on quantum computers [15] to the implementation of full-fledged quantum computers (e.g., Rigetti [16], ION-Q [17], Psi-Quantum [18], and so on). However, despite this rapid growth, because quantum computing as a field brings together many different disciplines, there is currently a shortage of engineers who understand both the engineering aspects (e.g., microwave design) and the quantum aspects required to build a quantum computer [19]. The aim of this article is to introduce microwave engineers to quantum computing and demonstrate how the microwave community's expertise could contribute to that field.
Quantum computing stands at the frontier of computational revolution, promising to transform our ability to solve problems that remain intractable for today's most powerful classical computers. This article explores the fundamental principles of quantum computing, where quantum mechanical phenomena such as superposition and entanglement enable unprecedented parallel processing capabilities. We examine why quantum computers have become a focal point of global research and development, with potential applications ranging from drug discovery and climate modeling to breaking current encryption standards and optimizing complex logistics. The text delves into the various approaches being pursued in quantum computer development, including superconducting circuits, trapped ions, and topological qubits, while addressing the significant challenges of maintaining quantum coherence and minimizing errors. By examining both the theoretical framework and practical implementation efforts, this article provides a comprehensive overview of quantum computing's current state, its transformative potential, and the roadmap toward achieving quantum supremacy.
Quantum computing, and to an even greater extent quantum technology, is changing the world. Quantum computing is not an evolution of classical computer science; it is actually a revolution that completely changes the computing paradigm. Quantum computers are based on the principles of quantum mechanics, such as superposition and entanglement, and they seek to boost computational power exponentially. Many problems that have until now been impossible to solve, in practical terms, might very well be able to be addressed by means of quantum computing. The fact is that at the present time quantum computing is influencing most business sectors and research fields, due to its various promising applications. To make such applications become reality, quantum algorithms must be specially coded for these extremely different computers. Although some well-known quantum algorithms already exist, the need for quantum software will increase dramatically in the next years. In that context, quantum software has to be produced in a more industrial and controlled way, i.e., aspects such as quality, delivery, project management, or evolution of quantum software must be addressed. We are sure that quantum computing will be the main driver for a new software engineering golden age during the present decade of the 2020s.
Abstract Quantum computing leverages fundamental quantum-mechanical phenomena—most notably superposition, entanglement, and quantum tunneling—to perform computations in ways that differ fundamentally from classical digital processing. Compared to conventional computing architectures, quantum systems promise significant reductions in computational time and potentially lower energy consumption for specific classes of problems. These advantages, combined with advances in nanoscale engineering and the slowing of traditional hardware scaling trends such as Moore’s Law, have led to substantial commercial and national-security-driven investments in quantum technologies over the past decade. A major milestone was reached when Google announced the experimental demonstration of “quantum supremacy,” showing that a quantum processor could execute a specific computational task infeasible for a classical supercomputer within practical time constraints. Although the demonstrated problem had no immediate practical application, this achievement marked a crucial step toward the development of quantum systems capable of delivering real-world computational advantages and provided a more precise technical framing of the concept of quantum advantage. Despite the fact that the mathematical foundations, programming models, and principal quantum algorithms were established in the 1990s, quantum computing remained largely confined to a specialized research community for decades. Today, the increasing accessibility of cloud-based quantum hardware calls for a broader dissemination of implementation-oriented knowledge among researchers and practitioners in computer science, software engineering, and related fields. The quantum programming paradigm differs fundamentally from classical programming models and often relies on physical and algebraic notations that may pose barriers to traditionally trained computer scientists. This series of articles provides a self-contained and concise introduction to quantum computing and its core algorithms, with a strong emphasis on practical implementation. Given that real quantum processors—such as those accessible via the IBM quantum ecosystem—are now available as cloud services, experimental validation can be conducted both on simulators and on actual hardware for small-scale inputs. While other platforms such as Rigetti and IonQ also offer cloud-based quantum computing services, this review focuses exclusively on the IBM quantum computing ecosystem.