We present a comprehensive framework for constructing various architectures of globally driven quantum computers, with a focus on superconducting qubits. Our approach leverages static inhomogeneities in the Rabi frequencies of qubits controlled by a common classical pulse -- a technique we refer to as the "crossed-qubit" method. We detail the essential components and design principles required to realize such systems, highlighting how global control can be harnessed to perform local operations, enabling universal quantum computation. This framework offers a scalable pathway toward quantum processors by striking a balance between wiring complexity and computational efficiency, with potential applications in addressing current challenges to scalability.
We present a comprehensive framework for constructing various architectures of globally driven quantum computers, with a focus on superconducting qubits. Our approach leverages static inhomogeneities in the Rabi frequencies of qubits controlled by a common classical pulse -- a technique we refer to as the "crossed-qubit" method. We detail the essential components and design principles required to realize such systems, highlighting how global control can be harnessed to perform local operations, enabling universal quantum computation. This framework offers a scalable pathway toward quantum processors by striking a balance between wiring complexity and computational efficiency, with potential applications in addressing current challenges to scalability.
Globally controlled superconducting qubit systems are regaining popularity due to their potential to solve one of the problems that most threatens the scalability of these platforms: the wiring problem. In fact, current quantum computers based on this technology rely on a local approach to qubit control, which, as the number of qubits increases, results in a cable density that interferes with the processor’s proper functioning. Adopting a global control approach makes it possible to reduce the number of cables and thus improve scalability. Since globally controlled architectures capable of universal quantum computation have already been proposed, the natural next step in the study of these platforms is the application of optimal control techniques. Indeed, given the global nature of the controls, optimization takes place across the entire system simultaneously, offering possibilities that would otherwise be unattainable with local control. The main objective of this work is to investigate these possible applications, focusing primarily on three aspects: digital quantum computation, quantum simulation, and the scalability of optimized pulses.
This paper explores a novel approach to achieving high-fidelity and scalable quantum computation through heterogeneous qubit connectivity within a topological quantum computing framework. The core challenge in topological quantum computing lies in effectively connecting qubits of diverse types – differing in their physical realization and control mechanisms – to enable complex quantum algorithms. This work proposes a system leveraging topological networks to establish these connections, capitalizing on quantum entanglement to facilitate information transfer and control across disparate qubit architectures. The proposed method addresses a critical bottleneck in the development of topological quantum computers by offering a fundamentally new strategy for heterogeneous qubit integration. The theoretical framework presented outlines the key principles and potential advantages of this approach, emphasizing the realization of robust, scalable, and versatile quantum systems. We detail the conceptual design, focusing on entanglement distribution and error mitigation strategies specific to this architecture. The ultimate goal is to demonstrate a pathway towards building quantum computers capable of tackling complex problems requiring diverse qubit capabilities.
This paper proposes a novel distributed computing architecture predicated on the precise control of quantum entanglement. The core claim is that by leveraging entanglement, it is possible to design a computing paradigm that surpasses the limitations of classical parallel computing. The proposed architecture utilizes entangled states to connect multiple quantum processors, enabling instantaneous state transfer and information sharing. This approach involves the development of new entanglement generation and control algorithms, optimized to manipulate quantum superposition and interference, thereby enhancing computational efficiency. The key innovation lies in moving beyond the bottleneck of classical communication inherent in traditional distributed systems. This architecture promises a fundamentally different approach to parallel computation, exploiting the unique properties of quantum mechanics. The presented framework offers a potential pathway towards scalable and highly efficient quantum computation, though significant technological challenges remain. The theoretical framework outlines the key components and operational principles of this new architecture.
We introduce the concept of quantum actuators as mediators for globally controlled quantum computation. Auxiliary quantum systems act as controllable elements that transiently store and release interaction energy, enabling the selective activation of multi-qubit gates within globally driven architectures. During compilation they remain passive and require no fine-grained local control, while during operation they allow for controlled activation of interactions and directional flow of quantum information. We provide a framework for embedding quantum actuators in globally controlled processors, showing how they enhance connectivity, enable long-range entangling operations, and bridge distant regions without increasing local control overhead. We discuss physical implementations and architectural strategies illustrating how these elements extend the capabilities of global-control schemes. A complementary interpretation in terms of quantum batteries naturally emerges, connecting global-control architectures with concepts from quantum thermodynamics while highlighting the distinct operational role of quantum actuators.
This paper presents a comprehensive review of quantum computing and the technological foundations of quantum processors. Quantum computing represents a transformative computational paradigm that leverages the fundamental principles of quantum mechanics—such as superposition, entanglement, and quantum interference—to solve complex problems that are intractable for classical computers. At the core of this paradigm lies the quantum processor, a specialized hardware system designed to initialize, control, and measure quantum bits (qubits) through precise gate operations and coherent interactions. The survey examines the essential theoretical concepts underlying quantum computation and provides a structured comparison of leading quantum processor platforms. Prominent architectures, including superconducting circuits, trapped-ion systems, and photonic implementations, are analyzed in terms of their physical mechanisms, scalability, coherence properties, and engineering challenges. Each platform offers distinct advantages and faces specific technical limitations related to noise, error correction, and fabrication complexity. In addition to reviewing hardware developments, this study highlights key obstacles in advancing quantum processors toward large-scale, fault-tolerant systems. Issues such as qubit stability, error mitigation, thermal management, and system integration are discussed to present a realistic perspective on current progress. Performance indicators including gate fidelity, coherence time, connectivity, and scalability are used to compare architectural approaches. The objective of this paper is to provide a clear and organized synthesis of recent advancements in quantum computing hardware, thereby offering researchers and practitioners a foundational reference to support continued innovation and development in this rapidly evolving field.
This paper proposes a novel approach to universal computation leveraging the precise control of quantum coherence degradation, often considered a detrimental effect in quantum computing. Instead of mitigating decoherence, we argue for its utilization as a fundamental resource. The core idea revolves around designing quantum circuits that exploit specific noise patterns to achieve precise control and manipulation of qubits. This architecture, termed the "Quantum Noise-Based Universal Computing Architecture," fundamentally shifts the paradigm by recognizing and harnessing the inherent variability introduced by quantum systems. We outline the theoretical framework, detailing the core mechanism which relies on carefully engineered circuits to orchestrate controlled decoherence, ultimately enabling universal computation. This approach circumvents the limitations inherent in traditional quantum computing methods that primarily focus on suppressing decoherence. The proposed architecture offers a pathway toward scalable and potentially more robust quantum computation.