Effects of interactions and disorder on the compressibility of two-dimensional electron and hole systems

✍ Scribed by A. K. Savchenko; E. A. Galaktionov; G. D. Allison; M. M. Fogler; S. S. Safonov; M. Y. Simmons; D. A. Ritchie

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 139 KB
• Volume: 3
• Category: Article
• ISSN: 1862-6351
• DOI: 10.1002/pssc.200562760

✦ Synopsis

Abstract

We have studied the thermodynamic compressibility of 2D electron and 2D hole gases near the apparent metal‐insulator transition, in the ranges of the interaction parameter r~s~ =1–2.5 and r~s~ =10–30, respectively. Nonmonotonic dependence of the inverse compressibility on the carrier density is observed with an upturn at low densities. Despite the large difference in r~s~ , this behaviour of inverse compressibility in both electron and hole systems can be quantitatively accounted for by a nonlinear screening of disorder by the carriers, in particular, by the disorder‐driven proliferation of depletion regions in the 2D channel. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)