Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nuclear Magnetic Resonance Imaging with 90 nm Resolution   Magnetic resonance imaging, based on the manipulation and detection of
nuclear spins, is a powerful imaging technique that typically operates on the
scale of millimeters to microns. Using magnetic resonance force microscopy, we
have demonstrated that magnetic resonance imaging of nuclear spins can be
extended to a spatial resolution better than 100 nm. The two-dimensional
imaging of 19F nuclei was done on a patterned CaF2 test object, and was enabled
by a detection sensitivity of roughly 1200 nuclear spins. To achieve this
sensitivity, we developed high-moment magnetic tips that produced field
gradients up to 1.4x10^6 T/m, and implemented a measurement protocol based on
force-gradient detection of naturally occurring spin fluctuations. The
resulting detection volume of less than 650 zl represents 60,000x smaller
volume than previous NMR microscopy and demonstrates the feasibility of pushing
magnetic resonance imaging into the nanoscale regime.

15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg