Spin susceptibility and effective mass of a 2D electron system in GaAs heterostructures towards the weak interacting regime

• Published in: Physica. E, Low-dimensional systems & nanostructures Low-dimensional systems & nanostructures, 2006-08, Vol.34 (1), p.260-263
• Main Authors: Tan, Y.-W., Zhu, J., Stormer, H.L., Pfeiffer, L.N., Baldwin, K.W., West, K.W.
• Format: Article
• Language: English
• Subjects: 2DEG; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Effective masses; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Exact sciences and technology; g-factor; Nonparabolicity; Physics; Spin susceptibility
• ISSN: 1386-9477; 1873-1759
• DOI: 10.1016/j.physe.2006.03.070

We determined the spin susceptibility χ and the effective mass m * towards the high density limit. Using a tunable GaAs/AlGaAs heterostructure, we can vary the 2D electron density from n = 1 × 10 10 cm - 2 to 4 × 10 11 cm - 2 . From ∼ 5 × 10 10 cm - 2 to our highest densities the mass values fall ∼ 10 % below the band mass of GaAs. The enhancement of χ decreases monotonically from a factor of 3 to 0.88 with increasing density. It continues to follow a previously observed power law, which leads to an unphysical limit for n → ∞ . Band structure effects affecting mass and g-factor become appreciable for large n and, when taken into account, lead to the correct limiting behavior of χ . Numerical calculations are in qualitative agreement with our data but differ in detail.