Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fully gapped superconductivity in centrosymmetric and
  non-centrosymmetric Re-B compounds probed with $\mu$SR   We present a comprehensive study on superconducting properties of Re$_7$B$_3$
and Re$_3$B through specific heat, magnetic susceptibility, resistivity, and
transverse and zero-field muon spin rotation/relaxation ($\mu$SR) experiments
on polycrystalline samples. Re$_7$B$_3$ (T$_C$ = 3.2~K) is a
non-centrosymmetric type-II ($\kappa$ $\approx$ 9.27) superconductor in the
weak coupling ($\lambda_{e-ph}$ = 0.54) regime. On the other hand, Re$_3$B
(T$_C$ = 5.19~K) is a centrosymmetric type-II ($\kappa$ $\approx$ 34.55)
superconductor in the moderate coupling ($\lambda_{e-ph}$ = 0.64) regime. Our
transverse-field $\mu$SR measurements show evidence for isotropically gapped
BCS type superconductivity with normalized gap ($\Delta_0/k_BT_C$) values of
1.69 (Re$_7$B$_3$) and 1.75 (Re$_3$B).

21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th