Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Superconductivity in alkali-earth metals doped phenanthrene   We discover superconductivity in alkali-earth metals doped phenanthrene. The
superconducting critical temperatures \emph{T}$_c$ are 5.6 K and 5.4 K for
Sr$_{1.5}$phenanthrene and Ba$_{1.5}$phenanthrene, respectively. The shielding
fraction of Ba$_{1.5}$phenanthrene exceeds 65%. The Raman spectra show 8
cm$^{-1}$/electron and 7 cm$^{-1}$/electron downshifts for the mode at 1441
cm$^{-1}$ due to the charge transfer to organic molecules from the dopants of
Ba and Sr. Similar behavior has been observed in A$_3$phenanthrene and
A$_3$C$_{60}$(A = K and Rb). The positive pressure effect in
Sr$_{1.5}$phenanthrene and Ba$_{1.5}$phenanthrene together with the lower $T_c$
with larger lattice indicates unconventional superconductivity in this organic
system.

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The categories of this paper are: hep-th
1
The categories of this paper are: cs
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg