Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Atomic Layer MoS2-Graphene van der Waals Heterostructure Nanomechanical
  Resonators   Heterostructures play significant roles in modern semiconductor devices and
micro/nanosystems in a plethora of applications in electronics,
optoelectronics, and transducers. While state-of-the-art heterostructures often
involve stacks of crystalline epi-layers each down to a few nanometers thick,
the intriguing limit would be heterto-atomic-layer structures. Here we report
the first experimental demonstration of freestanding van der Waals
heterostructures and their functional nanomechanical devices. By stacking
single-layer (1L) MoS2 on top of suspended single-, bi-, tri- and four-layer
(1L to 4L) graphene sheets, we realize array of MoS2-graphene heterostructures
with varying thickness and size. These heterostructures all exhibit robust
nanomechanical resonances in the very high frequency (VHF) band (up to ~100
MHz). We observe that fundamental-mode resonance frequencies of the
heterostructure devices fall between the values of graphene and MoS2 devices.
Quality (Q) factors of heterostructure resonators are lower than those of
graphene but comparable to those of MoS2 devices, suggesting interface damping
related to interlayer interactions in the van der Waals heterostructures. This
study validates suspended atomic layer heterostructures as an effective device
platform and opens opportunities for exploiting mechanically coupled effects
and interlayer interactions in such devices.

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The categories of this paper are: math
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The categories of this paper are: nlin
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The categories of this paper are: hep-lat
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-th
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The categories of this paper are: astro-ph
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The categories of this paper are: econ
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The categories of this paper are: ao-sci
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The categories of this paper are: math-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: physics
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The categories of this paper are: bayes-an
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The categories of this paper are: alg-geom
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The categories of this paper are: adap-org
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The categories of this paper are: eess
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The categories of this paper are: quant-ph