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Papers by Tom Boyd
Physica E: Low-dimensional Systems and Nanostructures, 2000
Hall-potential proÿles of a two-dimensional electron system (2DES) under quantum Hall (QH) condit... more Hall-potential proÿles of a two-dimensional electron system (2DES) under quantum Hall (QH) conditions have been investigated at T = 1:4 K with submicron resolution using a scanning force microscope sensitive to electrostatics. At an even integer Landau level ÿlling factor a rather nonlinear Hall-potential proÿle across the Hall-bar is observed. But at reduced magnetic ÿeld values corresponding to ÿlling factors slightly above this even integer value almost no Hall-potential drop across the bulk region is found. Instead, the potential clearly drops across prominent areas associated with the positions of incompressible strips that just had emerged at that ÿlling factor at both edges. This shows that the dominant incompressible strips of locally even integer ÿlling factor can decouple the bulk from the edge, thus demonstrating the importance of the edge region for the Hall-ÿeld distribution even at non-integer ÿlling factors.
Physica E: Low-dimensional Systems and Nanostructures, 2000
Hall-potential proÿles of a two-dimensional electron system (2DES) under quantum Hall (QH) condit... more Hall-potential proÿles of a two-dimensional electron system (2DES) under quantum Hall (QH) conditions have been investigated at T = 1:4 K with submicron resolution using a scanning force microscope sensitive to electrostatics. At an even integer Landau level ÿlling factor a rather nonlinear Hall-potential proÿle across the Hall-bar is observed. But at reduced magnetic ÿeld values corresponding to ÿlling factors slightly above this even integer value almost no Hall-potential drop across the bulk region is found. Instead, the potential clearly drops across prominent areas associated with the positions of incompressible strips that just had emerged at that ÿlling factor at both edges. This shows that the dominant incompressible strips of locally even integer ÿlling factor can decouple the bulk from the edge, thus demonstrating the importance of the edge region for the Hall-ÿeld distribution even at non-integer ÿlling factors.