Near Total Electronic Spin Separation as Caused by Nuclear Dynamics: Perturbing a Real-Valued Conical Intersection with Complex-Valued Spin-Orbit Coupling

TL;DR

This paper demonstrates that nuclear dynamics near conical intersections, when perturbed by spin-orbit coupling, can lead to highly efficient spin selectivity, opening new avenues for spintronic device design and requiring correction in semiclassical simulations.

Contribution

It reveals how complex spin-orbit coupling influences nuclear pathways at conical intersections, resulting in large spin polarization effects.

Findings

Small spin-orbit coupling causes large spin selectivity.

Berry force significantly affects pathway selection.

Implications for designing spintronic devices and correcting semiclassical models.

Abstract

We investigate the nuclear dynamics near a real-valued conical intersection that is perturbed by a complex-valued spin-orbit coupling. For a model Hamiltonian with two outgoing channels, we find that even a small spin-orbit coupling can dramatically affect the pathway selection on account of Berry force, leading to extremely large spin selectivity (sometime as large as 100%). Thus, this Letter opens the door for organic chemists to start designing spintronic devices that use nuclear motion and conical intersections (combined with standard spin-orbit coupling) in order to achieve spin selection. Vice versa, for physical chemists, this Letter also emphasizes that future semiclassical simulations of intersystem crossing (which have heretofore ignored Berry force) should be corrected to account for the spin polarization that inevitably arises when dynamics pass near conical intersections.