Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Broken time-reversal symmetry probed by muon spin relaxation in the
  caged type superconductor Lu$_5$Rh$_6$Sn$_{18}$   The superconducting state of the caged type compound Lu$_5$Rh$_6$Sn$_{18}$
has been investigated by using magnetization, heat capacity, and muon-spin
relaxation or rotation ($\mu$SR) measurements and the results interpreted on
the basis of the group theoretical classifications of the possible pairing
symmetries and a simple model of the resulting quasiparticle spectra. Our
zero-field $\mu$SR measurements clearly reveal the spontaneous appearance of an
internal magnetic field below the transition temperature, which indicates that
the superconducting state in this material is characterized by the broken
time-reversal symmetry. Further the analysis of temperature dependence of the
magnetic penetration depth measured using the transverse field $\mu$SR
measurements suggest an isotropic $s$-wave character for the superconducting
gap. This is in agreement with the heat capacity behavior and we show that it
can be interpreted in terms of a non unitary triplet state with point nodes and
an open Fermi surface.

10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex
20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat