Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Moire structures in twisted bilayer graphene studied by transmission
  electron microscopy   We investigate imaging of moire structures in free-standing twisted bilayer
graphene (TBG) carried out by transmission electron microscopy (TEM) in
diffraction and in-line Gabor holography modes. Electron diffraction patterns
of TBG acquired at typical TEM electron energies of 80 - 300 keV exhibit the
diffraction peaks caused by diffraction on individual layers. However,
diffraction peaks at the scattering angles related to the periodicity of the
moire structure have not been observed in such diffraction patterns. We show
that diffraction on moire structure can create intense diffraction peaks if the
energy of the probing electrons is very low, in the range of a few tens of eV.
Experimental diffraction patterns of TBG acquired with low-energy electrons of
236 eV exhibiting peaks attributed to the moire structure periodicity are
shown. In holography mode, the intensity of the wave transmitted through the
sample and measured in the far-field can be enhanced or decreased depending on
the atomic arrangement, as for example AA or AB stacking. Thus, a decrease of
intensity in the far-field must not necessarily be associated with some
absorption inside the sample but can simply be a result of a particular atomic
arrangement. We believe that our findings can be important for exploiting
graphene as a support in electron imaging.

32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
21
The categories of this paper are: adap-org
6
The categories of this paper are: astro-ph
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn