On the Electron-Electron Interactions in Two Dimensions

Abstract

In this paper, we analyze several experiments that address the effects of electron-electron interactions in 2D electron (hole) systems in the regime of low carrier density. The interaction effects result in renormalization of the effective spin susceptibility, effective mass, and g*-factor. We found a good agreement among the data obtained for different 2D electron systems by several experimental teams using different measuring techniques. We conclude that the renormalization is not strongly affected by the material or sample-dependent parameters such as the potential well width, disorder (the carrier mobility), and the bare (band) mass. We demonstrate that the apparent disagreement between the reported results on various 2D electron systems originates mainly from different interpretations of similar "raw" data. Several important issues should be taken into account in the data processing, among them the dependences of the effective mass and spin susceptibility on the in-plane field, and the temperature dependence of the Dingle temperature. The remaining disagreement between the data for various 2D electron systems, on one hand, and the 2D hole system in GaAs, on the other hand, may indicate more complex character of electron-electron interactions in the latter system.Comment: Added refs; corrected typos. 19 pages, 7 figures. To be published in: Chapter 19, Proceedings of the EURESCO conference "Fundamental Problems of Mesoscopic Physics ", Granada, 200

Chapter 3 Transport in a Two-Dimensional Disordered Electron Liquid with Isospin Degrees of Freedom

“…Later similar behavior of resistivity was experimentally observed in a variety of 2D electron systems. [68][69][70][71][72][73] For the observed in Ref. 65,66 temperature behavior of resistivity an important role seems to be played by the electron spin.…”

Resistance noise scaling in a dilute two-dimensional hole system in GaAs

“…The observation of a metallic behavior at intermediate r s values, 4 < r s < 36, in 2D electron or hole systems (2DES or 2DHS) in high mobility silicon metal-oxide-semiconductor field effect transistors (Si-MOSFETs) and in certain heterostructures has raised the possibility of a new metallic phase due to the interactions [4][5][6][7] , in contradiction with the scaling theory of localization for independent particles 8 . The metallic behavior is defined by a decrease of the resistivity ρ for decreasing temperature T, for p s > p c where p c is a critical density.…”

“…When p s < p c , an insulating behavior occurs (dρ /dT < 0). This possible MIT has been intensively studied, and strongly debated [3][4][5][6][7] . At the present time, explanations of the metallic behavior by corrections to the standard independent particle picture, such as temperature-dependent interaction and screening effects [26][27][28][29][30][31][32][33][34][35][36][37][38] have been put forward.…”

Electron-Electron Interaction Effects in Quantum Hall Regime of GaN/AlGaN Heterostructures

“…Since electron-electron interaction influences both m * and g * , it is useful to analyze the value which is proportional to its product -the spin susceptibility χ * (χ * ∝ g * m * ). The increase in the spin susceptibility with interaction strength has been already experimentally confirmed in different two-dimensional systems (2DS) (Si-MOSFETs, GaAs/AlGaAs heterostructures, AlAs, and InGaAs/InAlAs) [1,2].…”