Enormously High Concentrations of Fluorescent Nitrogen‐Vacancy Centers Fabricated by Sintering of Detonation Nanodiamonds

Abstract

The cover picture shows a microfl uidic channel and the magnetochromatic microspheres it generates. From a single-synthesis environment, structural-colored microspheres are synthesized by combining an optofl uidic approach with a magnetic property tuning method. The main image features the dynamic color tuning capability of the method; differently colored microspheres are generated in a single microfl uidic channel, and color can be changed in real-time during the synthesis process. The microspheres are produced with controlled and heterogeneous optical properties. They comprise 1D chain arrangements of magnetic nanoparticles, as shown by the microsphere in the foreground. The magnetic nanoparticles enable the microspheres to have the unique structural color. Orientation-dependent color diffraction of the magnetochromatic microspheres can be utilized to form structural color patterns using a patterned magnet. For more information, please read the Communication "Real-Time Optofl uidic Synthesis of Magnetochromatic Microspheres for Reversible Structural Color Patterning" by S. Kwon and coworkers, beginning on page 1163.The frontispiece features the multistrata nanoparticle-a single-core, fi ve-layered nanostructure. It combines tunable, dual-peak, UV-vis-NIR spectrum extinction characteristics; trimodal imaging contrast; a simple synthesis; and facile surface modifi cation capabilities into a single <60-nm-diameter, multifunctional nanosphere that seeks to relieve current methodological limitations by coupling diagnostics and therapeutics into one single theranostic tool. The image shows a model of the interior, multilayered, metallodielectric structure, including a schematic of the fabrication protocol. For more information, please read the Communication "The Multistrata

Enhanced solid-state multispin metrology using dynamical decoupling

“…13,15,16 For some samples, the NV multispin T 2 is increased to >2 ms, where it begins to be limited by NV spin-lattice relaxation (T 1 ≈ 6 ms). These demonstrations of the utility of dynamical decoupling for solid-state multispin systems pave the way for scalable applications of quantum information processing and metrology in a wide range of architectures, including multiple NV centers in bulk diamond, 1,12,20 two-dimensional (2D) (thin-layer) arrays, 6,[21][22][23] and diamond nanostructures 24,25 ; as well as phosphorous donors in silicon 26,27 and quantum dots. 28 The NV center is composed of a substitutional nitrogen impurity and a vacancy on adjacent lattice sites in the diamond crystal [ Fig.…”

Room-temperature near-infrared silicon carbide nanocrystalline emitters based on optically aligned spin defects

“…An alternative approach is based on colour centres in nanodiamonds with a high PL efficiency 17 . The most prominent example is the nitrogen-vacancy (NV) defect [18][19][20] .…”

Nanodiamond molecular imaging with enhanced contrast and expanded field of view

“…We expect that with improvements in the imaging system and in the nanodiamond contrast agent, nanodiamond imaging may become a useful imaging technique for imaging at depths of 2 to 3 cm or more, which should be applicable to small-animal molecular imaging and potentially to clinical molecular imaging. However, in order to make the technique practical, work needs to be done in realizing the high concentrations of NV in nanodiamond whose existence has been proven by Baranov et al 17 but which has not yet been done in a reproducible, high-yield, and scalable manner.…”

“…16 This is due to the NV's excellent quantum properties; even in nanodiamond, an NV might have a spin relaxation (T 1 ) time of ∼1 ms and a spin coherence time (T 2 ) of ∼1 μs. 17 The key features of the center that we exploit are optically induced spin polarization and optical spin readout.…”