Electron-electron interaction correction and magnetoresistance in tilted fields in Si-based 2D systems

TL;DR

This study investigates how electron-electron interactions affect conductivity and magnetoresistance in disordered 2D silicon systems under tilted magnetic fields, revealing the dependence on magnetic field modulus and challenging previous explanations for large magnetoresistance.

Contribution

It provides experimental evidence that electron-electron interaction corrections depend on magnetic field magnitude in tilted fields and are not the sole cause of large magnetoresistance in Si-based 2D systems.

Findings

Interaction correction depends on magnetic field modulus in high fields.

Correction behaves as logarithm of magnetic field at high fields.

Electron-electron interactions are not the only factor in large magnetoresistance.

Abstract

We study diffusive electron-electron interaction correction to conductivity by analyzing simultaneously $\rho_{xx}$ and $\rho_{xy}$ for disordered 2D electron systems in Si in tilted magnetic field. Tilting the field is shown to be a straightforward tool to disentangle spin and orbital effects. In particular, by changing the tilt angle we prove experimentally that in the field range $g\mu_BB>k_BT$ the correction depends on modulus of magnetic field rather than on its direction, which is expected for a system with isotropic $g$-factor. In the high-field limit the correction behaves as $\ln (B)$, as expected theoretically (Lee, Ramakrishnan, Phys. Rev. B{\bf 26}, 4009 (1982)). Our data prove that the diffusive electron-electron interaction correction to conductivity is not solely responsible for the huge and temperature dependent magnetoresistance in parallel field, typically observed in Si-MOSFETs.