Controllable atomic-scale quantum systems hold great potential as sensitive tools for nanoscale imaging and metrology. Possible applications range from nanoscale electric and magnetic fi eld sensing to single photon microscopy,Coach Factory Outlet, quantum information processing, and bioimaging. At the heart of such schemes is the ability to scan and accurately position a robust sensor within a few nanometers of a sample of interest,http://www.coachoutletfactory-sale.com/, while preserving the sensor's quantum coherence and readout fidelity. These combined requirements remain a challenge for all existing approaches that rely on direct grafting of individual solid state quantum systems or single molecules onto scanning-probe tips. Here,Coach Factory Online, we demonstrate the fabrication and room temperature operation of a robust and isolated atomic-scale quantum sensor for scanning probe microscopy. Speci fically,Coach Outlet, we employ a high-purity, single-crystalline diamond nanopillar probe containing a single Nitrogen-Vacancy (NV) color center. We illustrate the versatility and performance of our scanning NV sensor by conducting quantitative nanoscale magnetic fi eld imaging and near-fi eld single-photon fluorescence quenching microscopy. In both cases, we obtain imaging resolution in the range of 20 nm and sensitivity unprecedented in scanning quantum probe microscopy.
Experimental setup and probe fabrication for the scanning NV sensor. (a) Schematic of the setup consisting of a combined optical and atomic force microscope (AFM). We use a 532 nm laser (green arrows) to address the scanning NV center through its red fluorescence (red arrows). The scanning NV center resides in a diamond nanopillar (inset) and its proximity to the sample is maintained through AFM feedback. (b) Scanning electron microscope (SEM) image of a single-crystalline diamond nanopillar-probe (falsecolor coded in red) with a single NV center in its tip. (c) Brief depiction of the fabrication process for scanning single-crystalline diamond NV sensors. Electron-beam lithography is used to defi ne nanopillars and platforms from the top- and bottom-sides of a few micron thin diamond membrane. Patterns are then transferred to the diamond by reactive ion etching. (d) SEM image of a finalized array of diamond platforms with nanopillars. In all panels,www.coachoutletfactory-sale.com, dotted rectangles highlight diamond nanopillars.