Small- q anomaly in the dielectric function and high-temperature oscillations of the screening potential in a two-dimensional electron gas with spin-orbit coupling
Year: 1999
Type: article
Abstract: We study the static dielectric function $\ensuremath{\varepsilon}(q)$ of two-dimensional electron system with spin-orbit coupling in the frame of the random-phase approximation. We demonstrate that, in addition to the well-known ${2k}_{F}$-Kohn anomaly, spin-orbit coupling gives rise to the novel anomaly in the dielectric function at small ${q=q}_{0}\ensuremath{\ll}{k}_{F},$ where ${q}_{0}$ is the distance between two Fermi surfaces. As a result of this anomaly a large-distance behavior of the potential from a point charge exhibits (in addition to the conventional Friedel oscillations) oscillations with a period $2\ensuremath{\pi}{/q}_{0}.$ The remarkable feature of these oscillations is that they are not smeared out by the temperature. We show that the small-$q$ anomaly also modifies the indirect exchange interaction of localized magnetic moments (RKKY interaction). In the presense of spin-orbit coupling this interaction acquires a high-temperature component.
Authors: Guang-Hong Chen, M. E. Raikh
Institution: University of Utah
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1927650641