Intrinsic Low-Temperature Magnetism in SmB_{6}.

By means of new muon spin relaxation experiments, we disentangle extrinsic and intrinsic sources of low-temperature bulk magnetism in the candidate topological Kondo insulator (TKI) SmB_{6}. Results on Al-flux-grown SmB_{6} single crystals are compared to those on a large floating-zone-grown ^{154}Sm ^{11}B_{6} single crystal in which a 14 meV bulk spin exciton has been detected by inelastic neutron scattering. Below ∼10  K, we detect the gradual development of quasistatic magnetism due to rare-earth impurities and Sm vacancies.

Coexistence of ferromagnetic fluctuations and superconductivity in the actinide superconductor UTe.

We report low-temperature muon spin relaxation/rotation (SR) measurements on single crystals of the actinide superconductor UTe. Below 5 K we observe a continuous slowing down of magnetic fluctuations that persists through the superconducting transition temperature ( = 1.6 K), but we find no evidence of long-range or local magnetic order down to 0.

Raman and Brillouin scattering studies of bulk 2H-WSe2.

Raman and Brillouin spectroscopy were used to probe optic and acoustic phonons in bulk 2H-WSe2. Raman spectra collected under different polarization conditions allowed assignment of spectral peaks to various first- and second-order processes. In contrast to some previous studies, a Raman peak at  ∼259 cm(-1)was found not to be due to the A(1g) mode but to a second-order process involving phonons at either the M or K point of the Brillouin zone.