Mechanism for Electrostatically Generated Magnetoresistance in Chiral Systems without Spin-Dependent Transport

Area of Science:

• Condensed matter physics
• Spintronics
• Materials science

Background:

• Chirality-induced spin selectivity (CISS) effect and associated magnetoresistance (MR) in chiral materials coupled to ferromagnets are actively researched.
• Current interpretations of large MR in these systems often rely on spin-dependent transport.
• Discrepancies exist between experimental observations and theoretical models, particularly regarding Onsager reciprocity relations.

Purpose of the Study:

• To propose an alternative mechanism for two-terminal magnetoresistance in chiral systems interfaced with ferromagnets.
• To explain the observed experimental phenomena, including the failure of Onsager reciprocity relations.
• To provide a new framework for understanding electronic transport in these heterostructures.

Main Methods:

• Theoretical investigation of charge transport mechanisms.
• Analysis of electrostatic contact potential variations due to magnetization direction and chirality.
• Modeling of transport barriers modified by magnetic configurations.

Main Results:

• An alternative mechanism for MR is presented, attributing it to the modulation of transport barriers by the magnetization direction.
• This mechanism does not require spin transport and explains the sensitivity of linear response resistance to magnetization.
• The proposed mechanism resolves the apparent failure of Onsager reciprocity relations in the CISS effect.

Conclusions:

• The study offers a novel explanation for magnetoresistance in chiral-ferromagnet systems, distinct from spin-transport-based theories.
• The proposed mechanism, based on magnetization-dependent transport barriers, provides a consistent framework for experimental observations.
• Further experimental validation is suggested to confirm the proposed alternative mechanism.