attoPUBLICATIONS attoAFM | Page 29

Selected Applications attoAFM/CFM NV-Center Based Nanomagnetometry Given its premier mechanical and thermal stability, the attoAFM/CFM is the ideal platform for nanoscale magnetic imaging employing an AFM tip with a diamond nano- crystal that contains a single nitrogen-vacancy (NV) center [1]-[4]. Local magnetic fields are subsequently evaluated by measuring the Zeeman shifts of the NV defect spin sublevels. In the particular case of NV-center magnetometry, an external microwave field is emitted and tuned in frequency such that local spin resonance occurs. This condition can subsequently be detected by a decrease in photoluminescence intensity of the NV-center, referred to as ODMR (optically detected magnetic resonance). Using a Lock-in and feedback loop technique allows to maintain spin resonance while rastering the sample, allowing to record a local magnetic field map with nanometer resolution. In this example, magnetic imaging of a hard disk sample with random bit orientation was performed in the group of V. Jacques at LPQM, ENS-Cachan, France. [1] Example 1 (a,b): Quantitative imaging using ODMR based method with NV-center scanned at d 1 = 250 nm above the sample. (a) Schematic of the measurement. (b) Quan- titative magnetic field distribution recorded with the lockin technique (13 nm pixel size, 110 ms acquisition time per pixel). The inset shows a line-cut taken along the dashed white line in the image. [1] Example 2 (c,d): All-optical method with NV center closer to the sample surface. (c) Schematic of the measurement. (d) All optical photoluminescence image (no micro- wave field applied) recorded with the NV-scanning probe magnetometer in tapping mode (8 nm pixel size, 20 ms acquisition time per pixel). Comparisons with simulations indicates that the tip surface distance is roughly d 2  = 30 nm. Fine white dotted lines are plotted along the direction of the hard disk tracks as a guide for the eye. [1] References: [1] L. Rondin et al., Appl. Phys. Lett. 100, 153118 (2012) Related publications based on the attoAFM/CFM (2012-2016) [2] L. Thiel et al., Nature Nanotechnology (2016), doi:10.1038/nnano.2016.63 [3] Tetienne et al ., Science 344, 1366 (2014) [4] J.-P. Tetienne et al., Nature Communications 6, 6733 (2015) [5] A. Dréau et al., Phys. Rev. Lett. 113, 137601 (2014) [6] A. Dréau et al., Phys. Rev. Lett. 110, 060502 (2013) [7] L. Rondin et al., Nature communications 4, 2279 (2013) [8] J.-P. Tetienne et al., Phys. Rev. B 87, 235436 (2013) [9] J.-P. Tetienne et al., New J. Phys. 14, 103033 (2012) [10] A. Dréau et al., Phys. Rev. B 85, 134107 (2012) [11] L. Rondin et al., Appl. Phys. Lett. 100, 153118 (2012) attoMICROSCOPY Sophisticated Tools for Science