Magnetoresistivity and Acoustoelectronic Effects in a Tilted Magnetic Field in $p$-Si/SiGe/Si Structures with an Anisotropic $g$ Factor

TL;DR

This study investigates magnetoresistivity and acoustoelectronic effects in p-Si/SiGe/Si structures under tilted magnetic fields, revealing an angle-dependent g-factor and a ferromagnet-paramagnet phase transition at specific magnetic conditions.

Contribution

It provides the first measurement of the angle dependence of the effective g-factor and identifies a phase transition in p-Si/SiGe/Si structures under tilted magnetic fields.

Findings

Effective g-factor depends on magnetic field tilt angle.

A ferromagnet-paramagnet phase transition occurs at specific tilt angles.

Magnetoresistivity and acoustoelectronic effects are characterized in the studied structures.

Abstract

Magnetoresistivity $\rho _{xx}$ and $\rho _{xy}$ and the acoustoelectronic effects are measured in $p$-Si/SiGe/Si with an impurity concentration $p$ = 2 $\times $ 10$^{11}$ cm$^{-2}$ in the temperature range 0.3-2.0 K and an tilted magnetic field up to 18 T. The dependence of the effective $g$-factor on the angle of magnetic field tilt $\theta $ to the normal to the plane of a two dimensional $p$-Si/SiGe/Si channel is determined. A first order ferromagnet-paramagnet phase transition is observed in the magnetic fields corresponding to a filling factor $\nu $ = 2 at $\theta \approx $ 59$^\textrm{o}$-60$^\textrm{o}$.