2,799 research outputs found
Het meiobenthos van het Nederlands Continentaal Plat voorjaar 1991: rapportage in het kader van het Biologisch Monitoring Project
Radiation induced zero-resistance states in GaAs/AlGaAs heterostructures: Voltage-current characteristics and intensity dependence at the resistance minima
High mobility two-dimensional electron systems exhibit vanishing resistance
over broad magnetic field intervals upon excitation with microwaves, with a
characteristic reduction of the resistance with increasing radiation intensity
at the resistance minima. Here, we report experimental results examining the
voltage - current characteristics, and the resistance at the minima vs. the
microwave power. The findings indicate that a non-linear V-I curve in the
absence of microwave excitation becomes linearized under irradiation, unlike
expectations, and they suggest a similarity between the roles of the radiation
intensity and the inverse temperature.Comment: 3 color figures; publishe
Classification of Higher Dimensional Spacetimes
We algebraically classify some higher dimensional spacetimes, including a
number of vacuum solutions of the Einstein field equations which can represent
higher dimensional black holes. We discuss some consequences of this work.Comment: 16 pages, 1 Tabl
Quantum Hall Effect in a Two-Dimensional Electron System Bent by 90 Degrees
Using a new MBE growth technique, we fabricate a two-dimensional electron
system which is bent around an atomically sharp 90 degree corner. In the
quantum Hall regime under tilted magnetic fields, we can measure equilibration
between both co- and counter-propagating edge channels of arbitrary filling
factor ratio. We present here 4-point magnetotransport characterization of the
corner junction with filling factor combinations which can all be explained
using the standard Landauer-Buttiker edge channel picture. The success of this
description confirms the realization of a new type of quantum Hall edge
geometry.Comment: 4 pages, figures included Typographical errors corrected, reference
adde
Novel metallic and insulating states at a bent quantum Hall junction
A non-planar geometry for the quantum Hall (QH) effect is studied, whereby
two quantum Hall (QH) systems are joined at a sharp right angle. When both
facets are at equal filling factor nu the junction hosts a channel with
non-quantized conductance, dependent on nu. The state is metallic at nu = 1/3,
with conductance along the junction increasing as the temperature T drops. At
nu = 1, 2 it is strongly insulating, and at nu = 3, 4 shows only weak T
dependence. Upon applying a dc voltage bias along the junction, the
differential conductance again shows three different behaviors. Hartree
calculations of the dispersion at the junction illustrate possible
explanations, and differences from planar QH structures are highlighted.Comment: 5 pages, 4 figures, text + figs revised for clarit
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