Tuning the chiral orbital currents in a colossal magnetoresistive nodal line ferrimagnet

The ferrimagnetic nodal-line semiconductor Mn₃Si₂Te₆ exhibits colossal magnetoresistance (CMR) owing to the chiral orbital currents (COC). The COC is developed due to spin-orbit interaction (SOI) attributed to the tellurium (Te) atoms. Here, we observe that on chemical substitution of the Te atoms with selenium (Se), the COC, which runs along the Te-Te edges of the MnTe₆ octahedra, becomes weaker and thus affects the angular magnetoresistance (MR) of Mn₃Si₂Te₆. We find that the application of magnetic field along the easy axis leads to a considerable drop in resistance in substituted crystals, which otherwise exhibits weak MR. On the other hand, the CMR effect along the partially polarized magnetization direction is found to be only marginally affected due to the substitution and persists even for a significantly high concentration of Se.