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V. J. Goldman

Publications and source records attributed to V. J. Goldman.

27 records · Page 2Linked to original sources
arXiv2000

Invariance of Charge of Laughlin Quasiparticles

A Quantum Antidot electrometer has been used in the first direct observation of the fractionally quantized electric charge. In this paper we report experiments performed on the integer i = 1, 2 and fractional f = 1/3 quantum Hall plateaus extending over a filling factor range of at least 27%. We find the charge of the Laughlin quasiparticles to be invariantly e/3, with standard deviation of 1.2% and absolute accuracy of 4%, independent of filling, tunneling current, and temperature.

cond-mat.mes-hall↗
arXiv1999

QHE Today

I present a brief survey of important recent developments in the quantum Hall effect. The review covers both fractional and integer regimes, from an experimentalist's perspective. The topics include direct measurement of fractional charge, composite fermion Fermi surface, spin textures, and edge state (chiral Luttinger liquid) dynamics.

cond-mat.mes-hall↗
arXiv1999

On Anisotropic Transport in High Landau Levels

We would like to point out that: (i) according to the edge-bulk transport models for the quantum Hall regime, the direction of low bulk conductance is actually perpendicular to that expected naively; and (ii) the values of experimental "high resistance" peaks correspond to value of bulk conductance $\approx 1 e^{2}/h$.

cond-mat.mes-hall↗
arXiv1997

Energetics of Quantum Antidot States in Quantum Hall Regime

We report experiments on the energy structure of antidot-bound states. By measuring resonant tunneling line widths as function of temperature, we determine the coupling to the remote global gate voltage and find that the effects of interelectron interaction dominate. Within a simple model, we also determine the energy spacing of the antidot bound states, self consistent edge electric field, and edge excitation drift velocity.

cond-mat.mes-hall↗
arXiv1997

Magnetoresistance of composite fermions at ν=1/2

We have studied temperature dependence of both diagonal and Hall resistivity in the vicinity of $ν=1/2$. Magnetoresistance was found to be positive and almost independent of temperature: temperature enters resistivity as a logarithmic correction. At the same time, no measurable corrections to the Hall resistivity has been found. Neither of these results can be explained within the mean-field theory of composite fermions by an analogy with conventional low-field interaction theory. There is an indication that interactions of composite fermions with fluctuations of the gauge field may reconcile the theory and experiment.

cond-mat.mes-hall↗
arXiv1995

Logarithmic temperature dependence of conductivity at half-integer filling factors: Evidence for interaction between composite fermions

We have studied the temperature dependence of diagonal conductivity in high-mobility two-dimensional samples at filling factors $ν=1/2$ and 3/2 at low temperatures. We observe a logarithmic dependence on temperature, from our lowest temperature of 13 mK up to 400 mK. We attribute the logarithmic correction to the effects of interaction between composite fermions, analogous to the Altshuler-Aronov type correction for electrons at zero magnetic field. The paper is accepted for publication in Physical Review B, Rapid Communications.

cond-mat↗
arXiv1995

Peak Values of Conductivity in Integer and Fractional Quantum Hall Effect

The diagonal conductivity $σ_{xx}$ was measured in the Corbino geometry in both integer and fractional quantum Hall effect (QHE). We find that peak values of $σ_{xx}$ are approximately equal for transitions in a wide range of integer filling factors $3<ν<16$, as expected in scaling theories of QHE. This fact allows us to compare peak values in the integer and fractional regimes within the framework of the law of corresponding states.

cond-mat↗