Observation of Two-Terminal CISS Magnetoresistance with Nonmagnetic Contacts.

Abstract

Chiral materials contacted between a ferromagnet (FM) and a nonmagnet (NM) exhibit a chirality-dependent asymmetric magnetoresistance (MR) as the FM magnetization is flipped. This is considered to be a manifestation of the chirality induced spin selectivity (CISS) effect, in which chirality dependent spins generated in the medium are subsequently detected by the ferromagnetic spin detector. Here we show that this two-terminal asymmetric MR response is quite general and can arise even when an <i>achiral</i> medium is contacted by <i>nonmagnetic</i> electrodes, with no known spin detecting property. By controllably introducing chirality in the channel, we demonstrate how the <i>chirality-dependent</i> CISS MR manifests <i>even for nonspin-detecting electrodes</i>. The response, distinct from electromagnetochiral anisotropy (EMChA), remains unchanged in the standard configuration with FM/NM electrodes. Thus, observation of chirality-dependent MR in transport experiments does not necessarily relate chirality to spin, as commonly assumed in CISS literature.