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arXiv · 2402.00472

A mechanism for electrostatically generated magnetoresistance in chiral systems without spin-dependent transport

Sytze H. Tirion·Bart J. van Wees
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Abstract

Significant attention has been drawn to electronic transport in chiral materials coupled to ferromagnets in the chirality induced spin selectivity (CISS) effect. A large magnetoresistance (MR) is usually observed which is widely interpreted to originate from spin (dependent) transport. However, there are severe discrepancies between the experimental results and theoretical interpretations, most notably the apparent failure of the Onsager reciprocity relation in the linear response regime. We provide an alternative explanation for the mechanism of the two terminal MR in chiral systems coupled to a ferromagnet. For this we point out that it was observed that the electrostatic contact potential of chiral materials on a ferromagnet depends on the magnetization direction and chirality. In our explanation this causes the transport barrier to be modified by the magnetization direction, already in equilibrium, in the absence of a bias current. This strongly alters the charge transport through/over the barrier, not requiring spin transport. This provides a mechanism that allows the linear response resistance to be sensitive to the magnetization direction and also explains the failure of the Onsager reciprocity relations. We propose experimental configurations to confirm our alternative mechanism for MR.

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Sytze H. Tirion, Bart J. van Wees. 2024-02-01. A mechanism for electrostatically generated magnetoresistance in chiral systems without spin-dependent transport. https://doi.org/10.1021/acsnano.3c12925

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