Comprehensive Magnetotransport Characterizations of the Chiral Crystal Te

Real-space structural chirality is known to engender a range of exotic electronic effects including Kramers-Weyl fermions and chirality-induced spin selectivity (CISS). Tellurium (Te) is an elemental semiconductor with a distinct chiral crystal structure. A unidirectional magnetoresistance (MR) was reported in single-crystalline Te nanowires, which was interpreted as evidence for chirality-induced charge-to-spin conversion [1]. The nanowire morphology limited the measurements to a single collinear configuration of bias current and crystalline helical axis. Using hydrothermal growth, we have obtained high-quality single-crystal nanoplates of Te with 10s of mm in dimensions. The Te nanoplates were patterned into “L”-bar devices, which facilitated a comprehensive set of MR measurements, encompassing all combinations of the current and magnetic field directions in relation to the chiral crystal axis on a single device. Electrostatic gating from a bottom gate enabled ambipolar transport in the samples. Based on the results, we will discuss the correlations between the unidirectional MR and the CISS effect. Moreover, with the Te nanoplates, lateral devices are fabricated for direct detection of chirality-induced spin polarization. Our findings advance the understanding of CISS and spin transport in inorganic chiral crystals.

[1] F. Calavalle et al., Nat. Mat. 21, 526 (2022).