Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Polarization-dependent selection rules and optical spectrum atlas of
  twisted bilayer graphene quantum dots   Finding out how symmetry encodes optical polarization information into the
selection rule in molecules and materials is important for their optoelectronic
applications including spectroscopic analysis, display technology and quantum
computation. Here, we extend the polarization-dependent selection rules from
atoms to solid systems with point group descriptions via rotational operator
for circular polarization and $2$-fold rotational operator (or reflection
operator) for linear polarization. As a variant of graphene quantum dot (GQD),
twisted bilayer graphene quantum dot (TBGQD) certainly inherits GQD's
advantages including ultrathin thickness, excellent biocompatibility and shape-
and size-tunable optical absorption/emission. We then naturally ask how the
electronic structures and optical properties of TBGQDs rely on size, shape,
twist angle and correlation effects. We build plentiful types of TBGQDs with
$10$ point groups and obtain the optical selection rule database for all types,
where the current operator matrix elements identify the generalized
polarization-dependent selection rules. Our results show that both of the
electronic and optical band gaps follow power-law scalings and the twist angle
has the dominant role in modifying the size scaling. We map an atlas of optical
conductivity spectra for both size and twist angle in TBGQDs. As a result of
quantum confinement effect of finite size, in the atlas a new type of optical
conductivity peaks absent in twisted bilayer graphene bulk is predicted
theoretically with multiple discrete absorption frequencies from infrared to
ultraviolet light, enabling applications on photovoltaic devices and
photodetectors. The atlas and size scaling provide a full
structure/symmetry-function interrelation and hence offers an excellent
geometrical manipulation of optical properties of TBGQD as a building block in
integrated carbon optoelectronics.

22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
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The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th