Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Evidence for the first-order topological phase transition in a Kitaev
  spin liquid candidate $\alpha$-RuCl$ _3$   The Kitaev quantum spin liquid (QSL) on the two-dimensional honeycomb lattice
epitomizes an entangled topological state, where the spins fractionalize into
Majorana fermions. This state has aroused tremendous interest because it
harbors non-Abelian anyon excitations. The half-integer quantized thermal Hall
(HIQTH) conductance observed in $\alpha$-RuCl$_3$ is a key signature of these
excitations. However, the fate of this topologically nontrivial state at
intense fields remains largely elusive. Here, we report the thermal
conductivity $\kappa$ and specific heat $C$ of $\alpha$-RuCl$_3$ with in-plane
magnetic fields $H$. For the field direction perpendicular to the Ru-Ru bond,
where the HIQTH effect is observed, we find a discontinuous jump in $\kappa(H)$
and a peak anomaly in $C(H)$ at $\mu_0H^*\approx11$\,T, evidencing a weak
first-order phase transition. Remarkably, the HIQTH effect vanishes close to
$H^*$. Furthermore, we find that the spin-fractionalization feature is retained
well above $H^\ast$. These imply the emergence of the phase transition that
separates two QSL phases with distinct topological properties.

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The categories of this paper are: eess
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
2
The categories of this paper are: math
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The categories of this paper are: cmp-lg
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The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph