LAUSR

Topological semimetals host unique electronic phases with either Dirac or Weyl characteristic. One way to obtain the Weyl phase is to break the time-reversal symmetry by establishing magnetic ordering. We have investigated the electrical and magnetic properties of a magnetic Weyl semimetal candidate $\mathrm{BaMnS}{\mathrm{b}}_{2}$ under the application of magnetic field $(H)$ up to 35 T. We find that $\mathrm{BaMnS}{\mathrm{b}}_{2}$ undergoes three magnetic phase transitions with a ferromagnetic transition at ${T}_{\mathrm{C}}\ensuremath{\sim}690\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ and two antiferromagnetic transitions at ${T}_{\mathrm{N}1}\ensuremath{\sim}286\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ and ${T}_{\mathrm{N}2}\ensuremath{\sim}450\phantom{\rule{0.16em}{0ex}}\mathrm{K}$. At low temperatures, both the Shubnikov-de Haas and de Haas-van Alphen oscillations are observed by applying H along the $c$ axis of $\mathrm{BaMnS}{\mathrm{b}}_{2}$. Data analysis indicates that the oscillations result from a single band, and the system can reach the first Landau level at high H. Evidence for Zeeman splitting is also observed at low Landau levels, which yields the Land\'e factor $g\ensuremath{\sim}8.9\ensuremath{-}10.4$. In addition, thermal property measurements reveal very low phonon thermal conductivity and moderate thermopower. The coupling between charge, spin and lattice is discussed.