Abstract As a foundational technology in quantum information science (QIS), the manipulation and detection of quantum spins enable precise control, opening new avenues for significant advancements. Early research focused on macroscopic ensemble quantum systems, where electron spin resonance is used to coherently address electron spins within different ensembles. However, the low initialization efficiency and readout sensitivity of such systems hinder their further development. Unlocking the full potential of quantum technology, it is essential to achieve single‐spin precision. Various quantum systems, including color centers, quantum dots, atoms, and molecules, have been demonstrated the capability for single‐spin manipulation. The successful control of spin quantum states in these systems through diverse techniques has paved the way for new ideas and boundless possibilities in QIS. This review provides a comprehensive overview of recent significant advances in the field and explores future development directions, aiming to shed light on the ongoing evolution of QIS.
Abstract As a foundational technology in quantum information science (QIS), the manipulation and detection of quantum spins enable precise control, opening new avenues for significant advancements. Early research focused on macroscopic ensemble quantum systems, where electron spin resonance is used to coherently address electron spins within different ensembles. However, the low initialization efficiency and readout sensitivity of such systems hinder their further development. Unlocking the full potential of quantum technology, it is essential to achieve single‐spin precision. Various quantum systems, including color centers, quantum dots, atoms, and molecules, have been demonstrated the capability for single‐spin manipulation. The successful control of spin quantum states in these systems through diverse techniques has paved the way for new ideas and boundless possibilities in QIS. This review provides a comprehensive overview of recent significant advances in the field and explores future development directions, aiming to shed light on the ongoing evolution of QIS.
Coherent control and readout of single spins in solids is attracting considerable attention, owing to potential application of atomic- scale technologies in novel information processing protocols and sensing at the nanoscale [38]. Spins are particularly interesting candidates for achieving such control, owing to the long coherence time. This isolation from the environment makes the readout of individual spins quite challenging. It was shown that the magnetic moment associated with single quantum systems can be detected in transport measurements with single quantum dots [25] and defects in silicon [81]. Magnetic resonance force microscopy was also able to reach the ultimate sensitivity regime [65]. Recently developed optical readout techniques explore new avenue in single-spin de- tection by combining high-sensitivity optical microscopy techniques and conventional magnetic resonance control methods. Following detection of single molecular spin [80], quantum states associated with single defects in diamond were explored [29]. Experiments with single defects in diamond are particularly interesting owing to the long coherence time associated with spins of color centers. This chapter shows the basics of single-spin detection and highlights the importance of coherent control of spins in solids for novel quantum technologies.
Quantum computation provides great speedup over its classical counterpart for certain tasks. Spin system is one of the most important candidates to realize quantum computations. The initialization, readout and quantum gate operations of spin-qubits can be accomplished by advanced spin resonance techniques, which include nuclear magnetic resonance, electron paramagnetic resonance and optically detected magnetic resonance. This review aims to summarize recent experimental progresses in spin-based quantum computing. Preserving quantum states, precise quantum operations, quantum algorithms and quantum simulations on spin systems are reviewed. The fast improvement of quantum technology motivated by quantum computations results in recent progress in spin magnetic resonance in nanoscale. This review also introduces the achievements in nanoscale magnetic resonance with Nitrogen vacancy centers in diamonds.
Abstract Within the framework of quantum information and quantum processing, spin quantum systems are one of the most promising technologies, so they are extensively studied nowadays. It has provided several notable applications centred around the manipulation and control of spin ensembles through magnetic fields, particularly in Nuclear Magnetic Resonance. Also, such control is crucial for the settlement of qubit states and the construction of quantum gates. In this work, a review of methods to get the single spin dynamics is presented, thus regarding the simplest analytical solutions, the rotating frame approach, and general numerical procedures. Besides, some applications such as Evolution-loops, Spin-echo, and local Quantum gates are discussed. Finally, we deal with adiabatic pulses to explore a recent research implementation of quantum memories using single-spin systems.
Nitrogen-vacancy (NV) centers in diamond have recently emerged as a unique platform for fundamental studies in quantum information and nanoscience. The special properties of these impurity centers allow robust, room-temperature operation of solid-state qubits and have enabled several remarkable demonstrations in quantum information processing and precision nanoscale sensing. This article reviews the recent advances in magnetic and optical manipulation of the NV center’s quantum spin and their importance for prospective applications. We discuss how quantum control of individual centers can be harnessed for the protection of NV-center spin coherence, for multiqubit quantum operations in the presence of decoherence, and for high-fidelity initialization and readout. We also discuss the progress in resonant optical control, which has led to interfaces between spin and photonic qubits and may lead to spin networks based on diamond photonics. Many of these recently developed diamond-based technologies constitute critical components for the future leap toward practical multiqubit devices.
Abstract Quantum control allows a wide range of quantum operations employed in molecular physics, nuclear magnetic resonance and quantum information processing. Thanks to the existing microelectronics industry, semiconducting qubits, where quantum information is encoded in spin or charge degree freedom of electrons or nuclei in semiconductor quantum dots, constitute a highly competitive candidate for scalable solid-state quantum technologies. In quantum information processing, advanced control techniques are needed to realize quantum manipulations with both high precision and noise resilience. In this review, we first introduce the basics of various widely-used control methods, including resonant excitation, adabatic passage, shortcuts to adiabaticity, composite pulses, and quantum optimal control. Then we review the practical aspects in applying these methods to realize accurate and robust quantum gates for single semiconductor qubits, such as Loss–DiVincenzo spin qubit, spinglet-triplet qubit, exchange-only qubit and charge qubit.
Quantum computing represents a monumental leap in computational technology, leveraging the principles of quantum mechanics to solve complex problems at unprecedented speeds. Unlike classical computers, which rely on bits as the smallest unit of information, quantum computers utilize qubits that can exist in multiple states simultaneously, enabling them to perform many calculations at once. This paper delves into the foundational concepts of quantum computing, including superposition, entanglement, and quantum gates, and explores its potential applications across various domains, such as cryptography, drug discovery, optimization problems, and artificial intelligence. We will discuss current advancements in quantum technology, high-lighting key breakthroughs and the progress made by leading research institutions and companies. Furthermore, this paper addresses the significant challenges that quantum computing faces, including error rates, qubit coherence, and scalability, which hinder its widespread adoption. By examining these facets, we aim to provide a comprehensive overview of how quantum computing could transform various fields and the hurdles that must be overcome to realize its full potential, ultimately suggesting future directions for research and development in this revolutionary area of technology.