Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Atomic-resolution elemental mapping at cryogenic temperatures enabled by
  direct electron detection   Spectroscopic mapping by scanning transmission electron microscopy coupled
with electron energy loss spectroscopy (STEM-EELS) is a powerful technique for
determining the structure and chemistry of a wide range of materials and
interfaces. The extension of this technique to cryogenic temperatures opens the
door to new experiments across many fields including materials physics, energy
storage and conversion, and biology. Such experiments, however, often face
signal limitations due to sample sensitivity or the need for rapid data
acquisition under less stable cryogenic conditions. Compared to traditional
indirect detection systems such as charge coupled devices (CCDs), direct
electron detectors (DEDs) offer improved detective quantum efficiencies,
narrower point spread functions, and superior signal-to-noise ratios. Here, we
compare the performance of a Gatan K2 Summit DED to an UltraScan 1000 CCD for
use in signal-limited atomic-resolution STEM-EELS experiments. Due to its
improved point spread function, the DED's energy resolution remains comparable
to that of the CCD at a 5 times lower dispersion, providing simultaneous access
to a much broader total energy range without sacrificing spectral resolution.
More importantly, the benefits of direct detection enable a variety of
low-signal experiments, including atomic-resolution mapping of minor and high
energy edges such as the La-M$_{2,3}$ edge at 1123 eV and the Bi-M$_{4,5}$ edge
at 2580 eV. For rapid acquisitions at 400 spectra per second, elemental maps
recorded with the DED show an up to 40 percent increase in atomic lattice
fringe contrast compared to those acquired with the CCD. Taking advantage of
these performance improvements and the fast readout of the K2 DED, we use
direct detection STEM-EELS to demonstrate atomic-resolution elemental mapping
at cryogenic temperatures.

8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
6
The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg