Measurement of the Hall current density in a Corbino geometry 2D electron gas

We have investigated the distribution of the Hall current in a Corbino geom etry two-dimensional electron gas (2DEG) under quantum Hall effect conditio ns by measuring the induced magnetic moment. The magnetic moment near integ er filling factor shows oscillations around the quantized value, which refl ect a spatial redistribution of the Hall current density. The results show that at integer filling factor the local Hall conductivity in a high mobili ty sample is not quantized. Between integer filling factor the normal Hall current with the expected magnitude V(r)nu e(2)/h is measured, showing the reliability of the technique. [S0163-1829(99)03911-9].