Type

Database

Creator

Date

Thumbnail

# Search results

122 records were found.

## Flatland Electrons in High Magnetic Fields

Comment: Review paper, to be published in book series "High Magnetic Fields: Science and Technology" edited by Fritz Herlach and Noboru Miura, World Scientific Co

## Interaction and disorder in bilayer counterflow transport at filling factor one

Comment: 4 pages, 3 figures

## Apparent Metallic Behavior at B = 0 of a two-dimensional electron system in AlAs

We report the observation of metallic-like behavior at low temperatures and zero magnetic field in two dimensional (2D) electrons in an AlAs quantum well. At high densities the resistance of the sample decreases with decreasing temperature, but as the density is reduced the behavior changes to insulating, with the resistance increasing as the temperature is decreased. The effect is similar to that observed in 2D electrons in Si-MOSFETs, and in 2D holes in SiGe and GaAs, and points to the generality of this phenomenon.

## Strain-induced Fermi contour anisotropy of GaAs 2D holes

Comment: Accepted for publication in Phys. Rev. Lett

## Giant frictional drag in strongly interacting bilayers near filling factor one

Comment: 4 pages, 4 figures

## High-quality quantum point contact in two-dimensional GaAs (311)A hole system

We studied ballistic transport across a quantum point contact (QPC) defined in a high-quality, GaAs (311)A two-dimensional (2D) hole system using shallow etching and top-gating. The QPC conductance exhibits up to 11 quantized plateaus. The ballistic one-dimensional subbands are tuned by changing the lateral confinement and the Fermi energy of the holes in the QPC. We demonstrate that the positions of the plateaus (in gate-voltage), the source-drain data, and the negative magneto-resistance data can be understood in a simple model that takes into account the variation, with gate bias, of the hole density and the width of the QPC conducting channel.

## Dependence of Effective Mass on Spin and Valley Degrees of Freedom

Comment: 4 pages, 4 figures

## Enhancement of valley susceptibility upon complete spin-polarization

Measurements on a two-dimensional electron system confined to an AlAs quantum well reveal that for a given electron density the valley susceptibility, defined as the change in valley population difference per unit strain, is enhanced as the system makes a transition from partial to full spin polarization. This observation is reminiscent of earlier studies in which the spin susceptibility of AlAs electrons was observed to be higher in a single-valley system than its two-valley counterpart.

## Correlated States of Electrons in Wide Quantum Wells at Low Fillings: The Role of Charge Distribution Symmetry

Comment: submitted for publication

## Density dependence of valley polarization energy for composite fermions

In two-dimensional electron systems confined to wide AlAs quantum wells, composite fermions around the filling factor $\nu$ = 3/2 are fully spin polarized but possess a valley degree of freedom. Here we measure the energy needed to completely valley polarize these composite fermions as a function of electron density. Comparing our results to the existing theory, we find overall good quantitative agreement, but there is an unexpected trend: The measured composite fermion valley polarization energy, normalized to the Coulomb energy, decreases with decreasing density.