Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum oscillations of the superconductor LaRu$_2$P$_2$ : comparable
  mass enhancement $\lambda \approx 1$ in Ru and Fe phosphides   We have studied the angular dependent de Haas-van Alphen oscillations of
LaRu$_2$P$_2$ using magnetic torque in pulsed magnetic fields up to 60T. The
observed oscillation frequencies are in excellent agreement with the geometry
of the calculated Fermi surface. The temperature dependence of the oscillation
amplitudes reveals effective masses m*($\alpha$)=0.71 and m*($\beta$)=0.99
m$_e$, which are enhanced over the calculated band mass by $\lambda^{cyc}$ of
0.8. We find a similar enhancement $\lambda^{\gamma} \approx 1$ in comparing
the measured electronic specific heat ($\gamma = 11.5$ mJ/mol K$^2$) with the
total DOS from band structure calculations. Remarkably, very similar mass
enhancements have been reported in other pnictides LaFe$_2$P$_2$, LaFePO ($T_c
\approx 4K$), and LaRuPO, independent of whether they are superconducting or
not. This is contrary to the common perceptions that the normal state
quasi-particle renormalizations reflect the strength of the superconducting
paring mechanism and leads to new questions about pairing in isostructural and
isoelectronic Ru- and Fe-pnictide superconductors.

37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg