Magnetoresistance from quenching of spin quantum correlation in organic semiconductors

TL;DR

This paper develops a theoretical model explaining organic magnetoresistance (OMR) as a result of quenching spin quantum correlations during incoherent hopping, aligning well with experimental observations.

Contribution

It introduces a novel theory linking spin quantum correlation quenching to OMR, providing a parameter-independent explanation consistent with experiments.

Findings

OMR includes a positive Lorentzian saturation component.

OMR features a negative small-field component.

Model explains isotope effects observed in experiments.

Abstract

We present a theory of organic magnetoresistance (OMR) based on the quenching of the quantum correlation between the carrier's spin and its local environment when the incoherent hopping takes place. We prove that this process contributes a spin-dependent prefactor to the attempt-to-escape frequency in the hopping rate, with its value modulated by the magnetic field. The resulting OMR exhibits a positive Lorentzian saturation component and a negative small-field component, which are independent of model parameters. These behaviors, with their isotope effects, are in good agreement with experimental results.