Many-body effects on the ${\rho }_{xx}$ ringlike structures in two-subband wells

Abstract

The longitudinal resistivity ${\rho }_{xx}$ of two-dimensional electron gases formed in wells with two subbands displays ringlike structures when plotted in a density--magnetic-field diagram, due to the crossings of spin-split Landau levels (LLs) from distinct subbands. Using spin density functional theory and linear response, we investigate the shape and spin polarization of these structures as a function of temperature and magnetic-field tilt angle. We find that (i) some of the rings "break" at sufficiently low temperatures due to a quantum Hall ferromagnetic phase transition, thus exhibiting a high degree of spin polarization ($\sim 50$%) within, consistent with the NMR data of Zhang \textit{et al.} [Phys. Rev. Lett. {\bf 98}, 246802 (2007)], and (ii) for increasing tilting angles the interplay between the anticrossings due to inter-LL couplings and the exchange-correlation (XC) effects leads to a collapse of the rings at some critical angle ${\theta }_c$, in agreement with the data of Guo \textit{et al.} [Phys. Rev. B {\bf 78}, 233305 (2008)].

4 pages, 3 figures

References in corpus (8)

• Two-subband quantum Hall effect in parabolic quantum wells
• Multiple Phases with the Same Quantized Hall Conductance in a Two-Subband System
• Landau Level Anticrossing Manifestations in the Phase Diagram Topology of a Two Subband System
• Exchange-correlation orbital functionals in current-density-functional theory: Application to a quantum dot in magnetic fields
• NMR Probing Spin Excitations in the Ring-Like Structure of a Two-Subband System
• Probing Quantum Hall Pseudospin Ferromagnet by Resistively Detected NMR
• Observation of an in-plane magnetic-field-driven phase transition in a quantum Hall system with SU(4) symmetry
• Collapse of ${\rho }_{xx}$ ringlike structures in 2DEGs under tilted magnetic fields

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