Angular dependence of magnetoresistance in strongly anisotropic quasi-two-dimensional metals for various Landau-level shapes

TL;DR

This paper presents quantum-mechanical calculations showing how the shape of Landau levels affects the angular dependence of magnetoresistance in quasi-2D metals, revealing significant differences in oscillation amplitude and spin current behavior.

Contribution

It demonstrates that the Landau level shape critically influences angular magnetoresistance oscillations and spin currents in quasi-2D metals, a novel insight for understanding anisotropic magnetotransport.

Findings

Gaussian Landau levels produce stronger AMRO than Lorentzian levels.

The ratio of conductivities varies significantly with Landau level shape.

Spin currents exhibit angular oscillations and phase shifts related to AMRO.

Abstract

We present the quantum-mechanical calculations of the angular dependence of interlayer conductivity $\sigma _{zz}(\theta )$ in a tilted magnetic field in quasi-2D layered metals. Our calculation shows that the LL shape is important for this angular dependence. In particular, the amplitude of angular magnetoresistance oscillations (AMRO) is much stronger for the Gaussian LL shape than for the Lorentzian. The ratio $\sigma_{zz}(\theta =0)/ \sigma_{zz}(\theta ->\pm 90^{\circ})$ is also several times larger for the Gaussian LL shape. AMRO and Zeeman energy splitting lead to a spin current. For typical organic metals and for a medium magnetic field 10T this spin current is only a few percent of the charge current, but its value may almost reach the charge current for special tilt angles of magnetic field. The spin current has strong angular oscillations, which are phase-shifted as compared to the usual AMRO.