Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Large and homogeneous mass enhancement in the rattling-induced
  superconductor KOs$_2$O$_6$   We have determined the Fermi surface in KOs$_2$O$_6$ ($T_c$ = 9.6 K and
$B_{c2} \sim$ 32 T) via de Haas-van Alphen (dHvA) oscillation measurements and
a band structure calculation. We find effective masses up to 26(1) $m_e$ ($m_e$
is the free electron mass), which are unusually heavy for compounds where the
mass enhancement is mostly due to electron-phonon interactions. Orbit-resolved
mass enhancement parameters $\lambda_{dHvA}$ are large but fairly homogeneous,
concentrated in the range 5 -- 8. We discuss origins of the large homogeneous
mass enhancement in terms of rattling motion of the K ions.

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The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph