We study the crossover behavior of the Hall resistance between the integer quantum Hall regime and a regime dominated by the Aharonov-Bohm oscillations, in a system of 4-probe quantum dot with an artificial impurity confined inside. In a previous study [M. Lei, N.J. Zhu and Hong Guo, Phys. Rev. B. 52, 16784, (1995)], a peculiar set of symmetry relations between various scattering probabilities ...

The Hall response provides an important characterization of strongly correlated phases of matter. We study the Hall conductivity of interacting bosons on a lattice subjected to a magnetic field. We show that for any density or interaction strength, the Hall conductivity is characterized by an integer. We find that the phase diagram is intersected by topological transitions between different val...

The low-temperature Hall resistivity rxy of La2/3A1/3MnO3 single crystals ~where A stands for Ca, Pb, and Ca, or Sr! can be separated into ordinary and anomalous contributions, giving rise to ordinary and anomalous Hall effects, respectively. However, no such decomposition is possible near the Curie temperature which, in these systems, is close to metal-to-insulator transition. Rather, for all ...

I discuss recent work on the phase of the transmission coefficient for tunneling through a quantum dot in the quantum Hall effect regime. The effects of electron—electron interaction on this phase is investigated with the use of finite-size bosonization techniques combined with perturbation theory resummation. New non-Fermi-liquid phenomena are predicted in the fractional quantum Hall regime th...

The low-temperature magnetoresistance of parabolic quantum wells displays pronounced minima between integer filling factors. Concomitantly the Hall effect exhibits overshoots and plateaulike features next to well-defined ordinary quantum Hall plateaus. These effects set in with the occupation of the second subband. We discuss our observations in the context of single-particle Landau fan charts ...

We investigate the W∞ algebra in the integer quantum Hall effects. Defining the simplest vacuum, the Dirac sea, we evaluate the central extension for this algebra. A new algebra which contains the central extension is called the W1+∞ algebra. We show that this W1+∞ algebra is an origin of the KacMoody algebra which determines the behavior of edge states of the system. We discuss the relation be...

In situ transport measurements on disordered polycrystalline Fe films reveal a logarithmic temperature dependence of the longitudinal Rxx and anomalous Hall Rxx resistances at low temperatures and a heretoforeunobserved scaling behavior in which the relative changes in Rxx and Rxy are found to be equal. Accordingly, the anomalous Hall conductivity is non-zero with a logarithmic temperature depe...

The " exotic " particle model with non-commuting position coordinates , associated with the two-parameter central extension of the planar Galilei group, can be used to derive the ground states of the Fractional Quantum Hall Effect. The relation to other NC models is discussed. Anomalous coupling is presented. Similar equations arise for a semiclassical Bloch electron, used to explain the anoma-...

The fluctuation-induced Hall electromotive force, [deltaJ x deltaB]/nee, is experimentally measured in the high-temperature interior of a reversed-field pinch plasma by a fast Faraday rotation diagnostic. It is found that the Hall dynamo effect is significant, redistributing (flattening) the equilibrium core current near the resonant surface during a reconnection event. These results imply that...

Graphene is a two-dimensional carbon material with a honeycomb lattice and Dirac-like low-energy excitations. When Zeeman and spin-orbit interactions are neglected, its Landau levels are fourfold degenerate, explaining the 4e2/h separation between quantized Hall conductivity values seen in recent experiments. In this Letter we derive a criterion for the occurrence of interaction-driven quantum ...