We demonstrate the initialization of a single quantum-dot hole spin with high fidelity (lower bound $>97%$), on picosecond time scales, and without the need for magnetic fields. Using the initialization scheme based on rapid electric-field ionization of a resonantly excited exciton, this is achieved by employing a self-assembled quantum dot with a low conduction-to-valence band offset ratio, allowing control of the relative electron and hole tunneling rates over three orders of magnitude. This large difference in tunneling rates could permit spin-storage efficiencies $>99.5%$ by fast-switching to a low electric-field condition. Our results may provide a practical route towards ultrafast high-fidelity initialization of individual quantum-dot hole spins for the implementation of quantum error correction in a scalable spin-based quantum computer.

Hexagonal boron nitride is rapidly gaining interest as a platform for photonic quantum technologies, due to its two-dimensional nature and its ability to host defects deep within its large band gap that may act as room-temperature single-photon emitters. In this review paper we provide an overview of (1) the structure, properties, growth and transfer of hexagonal boron nitride; (2) the creationof colour centres in hexagonal boron nitride and assignment of defects by comparison with ab initio calculations for applications in photonic quantum technologies; and (3) heterostructure devices for the electrical tuning and charge control of colour centres that form the basis for photonic quantum technology devices. The aim of this review is to provide readers a summary of progress in both defect engineering and device fabrication in hexagonal boron nitride based photonic quantum technologies.

Computer simulation and modeling of coupled heat and moisture transfer are becoming increasingly significant for accurate calculations of heat and moisture transfer. However, to solve their equations, the true component, λ, of apparent thermal conductivity, λ_app, as a function of temperature, moisture content, and material structure is required. An approach to the development of a comprehensive database for λ is discussed. Its key feature is demonstrated by the development of a theoretical model for λ and λ _app of two common building insulation materials — expanded polystyrene insulation and highly porous calcium silicate — for a wide range of temperature and moisture conditions.

Using density functional theory (DFT), we study charge transfer between hexagonal boron nitride (h-BN) point defects and graphene in h-BN/graphene heterostructures using illustrative examples of intrinsic defects: nitrogen vacancy, boron vacancy, nitrogen antisite, and boron antisite. We show that traditional methods that calculate charge transfer by spatial discrimination of charge to different atoms suffer from the misallocation of charge and introduce an alternative method that relies on the integration of the density of states (DOS). We also show that DFT calculations of charge transfer have cell size dependencies due to a change in the DOS in the vicinity of the defect levels. Our results indicate that the nitrogen and boron anitsites do not participate in charge transfer, whereas the nitrogen and boron vacancies experience the transfer of a whole electron. Additionally, we show that a change in the geometry of a defect corresponds to a change in the charge state of the defect. The results of this paper will be important for a wide variety of device applications that involve charge transfer between h-BN defects and graphene in h-BN/graphene heterostructures, while our methodology can be feasibly extended to a wide range of point defects and heterostructures.

Hydrogen is gaining attention as a fossil fuel alternative due to its potential to meet global energy demands. Producing hydrogen from water splitting is promising as a clean and sustainable fuel pathway. The hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are crucial in electrocatalytic water splitting for energy conversion and storage. However, water electrolysis faces challenges in cost, efficiency, and scalability. Alternative transition metal electrocatalysts and emerging 2D materials advance electrolysis research, though transitioning from academia to industry remains challenging. The introduction of 3D‐printing technologies has revolutionized electrode fabrication for HER and OER. This review explores integrating 3D‐printing technologies and surface functionalization with non‐noble metal‐based electrocatalysts and emerging 2D materials. It focuses on surface‐functionalized 3D‐printed electrodes using technologies like selective laser melting, stereolithography, and fused deposition modeling with non‐noble metal electrocatalysts such as transition metal oxides, hydroxides, and emerging 2D materials like transition metal carbide/nitride (MXenes) and transition metal dichalcogenides (TMDCs). The review highlights the opportunities and challenges in scalable fabrication, long‐term durability, and cost‐efficiency for practical implementation. Future research directions include exploring new materials for 3D printing and alternative electrocatalysts alongside leveraging theoretical and machine‐learning approaches to accelerate the development of competitive materials for water electrolysis.

Color centers in hexagonal boron nitride (hBN) have gained significant interest as single-photon emitters and spin qubits for applications in a wide range of quantum technologies. As the integration of these solid-state quantum emitters into electronic devices necessitates electrical control, it is essential to gain a deeper understanding of the mechanisms for charge control of these defect color centers in hBN/graphene heterostructures. In this article, we show that screening due to the encapsulation of hBN by graphene modifies the electrical levels of hBN, leading to charge transfer. Furthermore, we show that the charged defects have low-energy barriers for defect reorientation which can be overcome by moderate gate voltages. This study shows that accurate modeling of the charge state of the defect is necessary to be able to electrically control defects.