Interplay of Orbital Paramagnetism and Diamagnetism in Nanometer Scale 2DEG Strips.

The role of boundary corrections to Landau diamagnetism for macroscopic free electronic systems has been discussed [1–8], and orbital paramagnetic effects have been experimentally observed in small systems [9]. The correction terms can theoretically be either paramagnetic or diamagnetic depending on the increase in potential energy at the surface which defines the perimeter of the electron system. In this work calculations of orbital magnetism have been performed for nanometer scale 2DEG strips laterally confined by an attractive transverse parabolic potential. The emergence of orbital paramagnetism depends sensitively on areal electron density, strip width, and parabolic potential strength such as may be produced by a split gate with negative voltage applied. Selected graphical results display considerable variation in the orbital paramagnetic contribution compared to the Landau diamagnetic susceptibility. [ABSTRACT FROM AUTHOR]