Museum display - fractions of a Truth

Paper presented at the Wits History Workshop: Myths, Monuments, Museums; New Premises? 16-18 July, 199

Two-dimensional electron gas tilt-induced Landau level crossings

This work elucidates the novel behavior found in a two-dimensional electron gas (2DEG) under a tilted magnetic field in which the field's angle becomes the dominant factor in tuning the spin-splitting rather than the strength of the spin-orbit interaction. The 2DEG eigenvalues are derived with Rashba and Zeeman interactions for various tilt angles and they show crossing-free levels except at very high tilt. Moreover, concomitant with the crossings is the appearance of beats in the 2DEG density of states. The crossings from different levels occur consecutively at around 87^{\circ}. Similar new observations in Shubnikov-de Haas experimental measurements by Hatke et al. [1] attributed such phenomena to an in-plane-magnetic-field-induced increase in the effective mass. We show here that this behavior is inherent to a 2DEG where spin-orbit interaction and the in-plane magnetic field contribution are taken into account.Comment: 5 pages, 5 figure

Art from South Africa

The authors examine the role of the visual arts in the construction of the histories of South African cultural identity, with reference to social context, over-determination, transitional art, appropriation, acculturation and commodification. Includes a chronology of visual culture in South Africa between 1910 and 1990. Biographical notes. 17 bibl. ref