4 research outputs found
Multi-species optically addressable spin defects in a van der Waals material
Optically addressable spin defects hosted in two-dimensional van der Waals
materials represent a new frontier for quantum technologies, promising to lead
to a new class of ultrathin quantum sensors and simulators. Recently, hexagonal
boron nitride (hBN) has been shown to host several types of optically
addressable spin defects, thus offering a unique opportunity to simultaneously
address and utilise various spin species in a single material. Here we
demonstrate an interplay between two separate spin species within a single hBN
crystal, namely boron vacancy defects and visible emitter spins. We
unambiguously prove that the visible emitters are spins and
further demonstrate room temperature coherent control and optical readout of
both spin species. Importantly, by tuning the two spin species into resonance
with each other, we observe cross-relaxation indicating strong inter-species
dipolar coupling. We then demonstrate magnetic imaging using the
defects, both under ambient and cryogenic conditions, and
leverage their lack of intrinsic quantization axis to determine the anisotropic
magnetic susceptibility of a test sample. Our results establish hBN as a
versatile platform for quantum technologies in a van der Waals host at room
temperature
Creation of Boron Vacancies in Hexagonal Boron Nitride Exfoliated from Bulk Crystals for Quantum Sensing
Boron vacancies (VB–) in hexagonal boron -nitride (hBN) have sparked great interest in recent years due to their optical and spin properties. Since hBN can be readily integrated into devices where it interfaces a huge variety of other 2D materials, boron vacancies may serve as a precise sensor which can be deployed at very close proximity to many important materials systems. Boron vacancy defects may be produced by a number of existing methods, the use of which may depend on the final application. Any method should reproducibly generate defects with controlled density and desired pattern. To date, however, detailed studies of such methods are missing. In this paper, we study various techniques for the preparation of hBN flakes from bulk crystals and relevant postprocessing treatments, namely, focused ion beam (FIB) implantation, for creation of VB–s as a function of flake thickness and defect concentrations. We find that flake thickness plays an important role when optimizing implantation parameters, while careful sample cleaning proved important to achieve consistent results