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arXiv · 2606.17823

Tunneling amplifies chirality-induced spin selectivity and explains its current-direction invariance

Fedor Baranov·Virginia Gali·Gal Lemut·Maxim Breitkreiz
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Abstract

We propose a minimal model for chirality-induced spin selectivity (CISS) in dc transport through insulating chiral molecules, based on quantum tunneling and interaction-induced spin splitting. As a concrete realization of the latter, we consider a weak Zeeman interaction of the particle spin with the current-induced magnetic field, recently shown to occur in helical molecules. We show that quantum tunneling, combined with dissipation, amplifies the effect, so that even such a small spin-dependent perturbation can yield spin polarizations on the order of 100\% across a wide range of applied bias voltages. Furthermore, our tunneling scenario naturally reproduces the characteristic CISS symmetry of the current-voltage dependence -- namely, the invariance of the spin-polarization sign under reversal of the current direction -- while fully respecting Onsager's reciprocity relations.

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Fedor Baranov, Virginia Gali, Gal Lemut, Maxim Breitkreiz. 2026-06-16. Tunneling amplifies chirality-induced spin selectivity and explains its current-direction invariance. https://arxiv.org/abs/2606.17823

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