Chirality-Induced Spin Polarization over Macroscopic Distances in Chiral Disilicide Crystals

A spin-polarized state is examined under charge current at room temperature without magnetic fields in chiral disilicide crystals NbSi2 and TaSi2. We found that a long-range spin transport occurs over ten micrometers in these inorganic crystals. A distribution of crystalline grains of different handedness is obtained via location-sensitive electrical transport measurements. The sum rule holds in the conversion coefficient in the current-voltage characteristics. A diamagnetic nature of the crystals supports that the spin polarization is not due to localized electron spins but due to itinerant electron spins. A large difference in the strength of antisymmetric spin-orbit interaction associated with 4d electrons in Nb and 5d ones in Ta is oppositely correlated with that of the spin polarization. A robust protection of the spin polarization occurs over long distances in chiral crystals.

Automated summary

A spin-polarized state was studied in chiral disilicide crystals NbSi2 and TaSi2 at room temperature without magnetic fields, where long-range spin transport occurred over ten micrometers. The conversion coefficient in the current-voltage characteristics adhered to a sum rule, while a diamagnetic nature suggested itinerant electron spins rather than localized ones were responsible for the spin polarization. In addition, a robust protection of spin polarization was observed in chiral crystals over long distances.