Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High-quality lithium niobate photonic crystal nanocavities   Lithium niobate (LN) exhibits unique material characteristics that have found
many important applications. Scaling LN devices down to a nanoscopic scale can
dramatically enhance light-matter interaction that would enable nonlinear and
quantum photonic functionalities beyond the reach of conventional means.
However, developing LN-based nanophotonic devices turns out to be nontrivial.
Although significant efforts have been devoted in recent years, LN photonic
crystal structures developed to date exhibit fairly low quality. Here we
demonstrate LN photonic crystal nanobeam resonators with optical Q as high as
10^5, more than two orders of magnitude higher than other LN nanocavities
reported to date. The high optical quality together with tight mode confinement
leads to extremely strong nonlinear photorefractive effect, with a resonance
tuning rate of 0.64 GHz/aJ, or equivalently 84 MHz/photon, three orders of
magnitude greater than other LN resonators. In particular, we observed
intriguing quenching of photorefraction that has never been reported before.
The devices also exhibit strong optomechanical coupling with gigahertz
nanomechanical mode with a significant f*Q product of 1.47*10^12 Hz. The
demonstration of high-Q LN photonic crystal nanoresonators paves a crucial step
towards LN nanophotonics that could integrate the outstanding material
properties with versatile nanoscale device engineering for diverse intriguing
functionalities.

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The categories of this paper are: nucl-th
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The categories of this paper are: hep-lat
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The categories of this paper are: chem-ph
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The categories of this paper are: math-ph
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The categories of this paper are: solv-int
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The categories of this paper are: mtrl-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: supr-con
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The categories of this paper are: q-alg
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The categories of this paper are: stat
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The categories of this paper are: ao-sci
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-ph
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The categories of this paper are: funct-an
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The categories of this paper are: plasm-ph
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The categories of this paper are: alg-geom