Spin-active defects in hexagonal boron nitride

Abstract

Quantum technology grown out of quantum information theory, including quantum communication, quantum computation and quantum sensing, not only provides powerful research tools for numerous fields, but also is expected to go to civilian use in the future. Solid-state spin-active defects are one of promising platforms for quantum technology, and the host materials include three-dimensional diamond and silicon carbide, and the emerging two-dimensional hexagonal boron nitride (hBN) and transition-metal dichalcogenides. In this review, we will focus on the spin defects in hBN, and summarize theoretical and experimental progresses made in understanding properties of these spin defects. In particular, the combination of theoretical prediction and experimental verification is highlighted. We also discuss the future advantages and challenges of solid-state spins in hBN on the path towards quantum information applications.

Detection of Paramagnetic Spins with an Ultrathin van der Waals Quantum Sensor

“…33−41 hBN is an exfoliable, air-stable vdW material and is host to a robust, optically addressable spin defect, the negatively charged boron vacancy (V B − ). 33,42 The V B − defect can be introduced in the hBN lattice through a variety of irradiation methods, 43,44 and several demonstrations of quantum sensing have subsequently been reported, including the detection and imaging under ambient conditions of static magnetic fields, temperature, and strain 34,37−40 and the imaging of magnetic noise from a ferromagnetic material at cryogenic temperatures. 41 In this work, we demonstrate the detection of magnetic noise from paramagnetic spins with an hBN quantum sensor under ambient conditions.…”

“…to a trilayer flake with the defect in the middle layer) and with no surface-induced background magnetic noise, which could lead to future opportunities in ultrasensitive quantum sensing. Recently, hexagonal boron nitride (hBN) has emerged as a promising material platform to realize such ultrathin quantum sensors. − hBN is an exfoliable, air-stable vdW material and is host to a robust, optically addressable spin defect, the negatively charged boron vacancy (V B – ). , The V B – defect can be introduced in the hBN lattice through a variety of irradiation methods, , and several demonstrations of quantum sensing have subsequently been reported, including the detection and imaging under ambient conditions of static magnetic fields, temperature, and strain ,− and the imaging of magnetic noise from a ferromagnetic material at cryogenic temperatures …”

Quantum sensing of paramagnetic spins in liquids with spin qubits in hexagonal boron nitride

“…Spin defects in hBN [16,37] provide a promising solution to the challenges of creating high-quality spin color centers near surfaces [12,38]. hBN can be stable at the limit of a monolayer and have no dangling bond on the surface.…”

Greatly Enhanced Emission from Spin Defects in Hexagonal Boron Nitride Enabled by a Low-Loss Plasmonic Nanocavity

“…Specifically, hBN has emerged as a promising platform that hosts QEs with remarkable properties such as strain- 10 and electric-fieldtunable 11 optical constants, emission ranging from ultraviolet 12 to near-infrared 13 wavelengths, and spin-selective optical transitions. 14 Consequently, a significant amount of research has been focused on understanding the properties of these defects, 15−19 deterministic creation processes, 20−24 and their integration with photonic structures. 25−28 Recently, the negatively charged boron-vacancy (V B − ) spin defect (Figure 1a) in hBN 15−19,29−31 has been widely studied for its potential as a quantum sensor for magnetic fields, temperature, pressure, and nuclear spins.…”

“…Solid-state quantum emitters (QEs) are the central building blocks for emerging quantum technologies, including quantum information processing, quantum communication, and quantum sensing. − In recent years, significant effort has been made with the development of QEs in two-dimensional van der Waals (vdW) materials such as transition-metal dichalcogenides (TMDC) , and hexagonal boron nitride (hBN). , The two-dimensional nature of these host materials and their robust chemical properties offer unparalleled advantages for integrating these QEs with plasmonic and photonic structures into hybrid quantum devices. Specifically, hBN has emerged as a promising platform that hosts QEs with remarkable properties such as strain- and electric-field-tunable optical constants, emission ranging from ultraviolet to near-infrared wavelengths, and spin-selective optical transitions . Consequently, a significant amount of research has been focused on understanding the properties of these defects, − deterministic creation processes, − and their integration with photonic structures. − …”