Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dynamic Surface Modification due to Effusion of Na in Na$_2$IrO$_3$   The honeycomb lattice iridate Na$_2$IrO$_3$ shows frustrated magnetism and
can potentially display Kitaev-like exchange interactions. Recently, it was
shown that the electronic properties of the surface of crystalline
Na$_2$IrO$_3$ can be tuned by Ar plasma treatment in a controlled manner
leading to various phases of matter ranging from a fully gapped to a metallic
surface, where the possibility of a charge-density wave (CDW) like transition
is also expected. Here, through direct imaging with an atomic force microscope
(AFM) in air, we show that the surface of crystalline Na$_2$IrO$_3$ evolves
rapidly as elemental Na effuses out of the interleave planes to the surface and
undergoes sublimation thereby disappearing from the surface gradually over
time. Using conductive AFM we recorded a series of topographs and surface
current maps simultaneously and found that the modification of the surface
leads to change in the electronic properties in a dynamic fashion until the
whole system reaches a dynamic equilibrium. These observations are important in
the context of the exotic electronic and magnetic properties that the surface
of Na$_2$IrO$_3$ displays.

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The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
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The categories of this paper are: q-fin
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The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: solv-int
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The categories of this paper are: chao-dyn
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The categories of this paper are: econ
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The categories of this paper are: hep-ex
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The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
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The categories of this paper are: alg-geom
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The categories of this paper are: atom-ph