Selected Application
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 nanocrystal 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.
Example 1 (a,b): Quantitative imaging using ODMR based method with NV-center
scanned at d1 = 250 nm above the sample. (a) Schematic of the measurement. (b) Quantitative 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.
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 microwave 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 d2 = 30 nm. Fine white dotted lines are
plotted along the direction of the hard disk tracks as a guide for the eye. [3]
References:
[1] L. Rondin et al., Appl. Phys. Lett. 100, 153118 (2012)
[2] L. Rondin et al., Nature Communications 4, 2279 (2013)
[3] J.-P. Tetienne et al., Phys. Rev. B 87, 235436 (2013)
[4] J.-P. Tetienne et al., Science 344, 1366-1369 (2014)
Further reading:
A. Dréau et al., Phys. Rev. B 85, 134107 (2012)
J.-P. Tetienne et al., New J. Phys. 14, 103033 (2012)
A. Dréau et al., Phys. Rev. Lett. 110, 060502 (2013)
A. Dréau et al., Phys. Rev. Lett. 113, 137601 (2014)
J.-P. Tetienne et al., Nature Communications 6, 6733 (2015)
attoMICROSCOPY
Sophisticated Tools for Science
attoAFM /CFM
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