Valley polarization dependence of nonreciprocal transport in a chiral semiconductor

We report that the strong spin-valley coupling in chiral tellurium can modify the electronic structures, and how it dominates the nonreciprocal transport. The observed nonreciprocal magnetoresistance shows anomalous suppression in high magnetic fields. This behavior contradicts the linearity of nonreciprocal signals to the fields observed in other materials. We find that the magnetic field-induced fully valley polarized states in tellurium trigger the deviation from the linearity. Our results establish the essential role of the valley degree of freedom for the cross-correlation phenomena in chiral materials, in addition to the previously discussed spin-charge coupling.