Magnetoresistivity in a Tilted Magnetic Field in p-Si/SiGe/Si Heterostructures with an Anisotropic g-Factor: Part II

Abstract

The magnetoresistance components ${\rho }_{xx}$ and ${\rho }_{xy}$ were measured in two p-Si/SiGe/Si quantum wells that have an anisotropic g-factor in a tilted magnetic field as a function of temperature, field and tilt angle. Activation energy measurements demonstrate the existence of a ferromagnetic-paramagnetic (F-P) transition for a sample with a hole density of $p$=2$\times 10^{11}$\,cm${}^{-2}$. This transition is due to crossing of the 0$\uparrow$ and 1$\downarrow$ Landau levels. However, in another sample, with $p$=7.2$\times 10^{10}$\,cm${}^{-2}$, the 0$\uparrow$ and 1$\downarrow$ Landau levels coincide for angles $\Theta$=0-70${}^{\text{o}}$. Only for $\Theta$ > 70${}^{\text{o}}$ do the levels start to diverge which, in turn, results in the energy gap opening.

5 pages, 6 figures

References in corpus (6)

• Highly Anisotropic Transport in the Integer Quantum Hall Effect
• Quantum Hall ferromagnets, cooperative transport anisotropy, and the random field Ising model
• Large Magnetoresistance of a Dilute $p$-Si/SiGe/Si Quantum Well in a Parallel Magnetic Field
• "Forbidden" transitions between quantum Hall and insulating phases in p-SiGe heterostructures
• Electronic Transport Properties of the Ising Quantum Hall Ferromagnet in a Si Quantum Well
• Magnetoresistivity and Acoustoelectronic Effects in a Tilted Magnetic Field in $p$-Si/SiGe/Si Structures with an Anisotropic $g$ Factor