Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Twisted bilayer graphene fabricated by direct bonding in a high vacuum   Twisted bilayer graphene (TBG), in which two monolayer graphene are stacked
with an in-plane rotation angle, has recently become a hot topic due to unique
electronic structures. TBG is normally produced in air by the tear-and-stack
method of mechanical exfoliation and transferring graphene flakes, by which a
sizable, millimeter-order area, and importantly clean interface between layers
are hard to obtain. In this study, we resolved these problems by directly
transferring the easy-to-exfoliate CVD-grown graphene on SiC substrate to
graphene in a high vacuum without using any transfer assisting medium and
observed electronic band modulations due to the strong interlayer coupling.

23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
6
The categories of this paper are: astro-ph
1
The categories of this paper are: cs
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th