Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Atomically Thin Resonant Tunnel Diodes built from Synthetic van der
  Waals Heterostructures   Vertical integration of two-dimensional van der Waals materials is predicted
to lead to novel electronic and optical properties not found in the constituent
layers. Here, we present the direct synthesis of two unique, atomically thin,
multi-junction heterostructures by combining graphene with the monolayer
transition-metal dichalocogenides: MoS2, MoSe2, and WSe2.The realization of
MoS2-WSe2-Graphene and WSe2-MoSe2-Graphene heterostructures leads toresonant
tunneling in an atomically thin stack with spectrally narrow room temperature
negative differential resistance characteristics.

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The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
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The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an