arXiv:0711.1294 · Physical Review B
Spin susceptibility of interacting two-dimensional electrons with anisotropic effective mass
Tayfun Gokmen, Medini Padmanabhan, Emanuel Tutuc, MANSOUR SHAYEGAN, S. De Palo, Saverio Moroni, Gaetano Senatore
Abstract
We report measurements of the spin susceptibility in dilute (${r}_{s}$ up to $\ensuremath{\approx}10$) AlAs two-dimensional (2D) electrons occupying a single conduction-band valley with an anisotropic in-plane Fermi contour, characterized by longitudinal and transverse effective masses ${m}_{l}$ and ${m}_{t}$. As the density is decreased, the spin susceptibility is significantly enhanced over its band value, reflecting the role of interaction. Yet the enhancement is suppressed compared to the results of quantum Monte Carlo based calculations that take the finite thickness of the electron layer into account but assume an isotropic effective mass equal to $\sqrt{{m}_{l}.{m}_{t}}$. Proper treatment of an interacting 2D system with an anisotropic effective mass therefore remains a theoretical challenge.