Single-Electron Charging Effects in Insulating Wires

We present measurements of the transport properties of 0.75-μm-long, narrow, insulating indium oxide wires and rings. These devices have no apparent tunnel barriers, yet they exhibit effects similar to those found in series arrays of very small-capacitance tunnel junctions: highly nonlinear I-V characteristics and a zero-bias conductance which is periodic in a voltage applied by means of a lateral gate. These effects are due to the influence of single-electron charging on transport through localized states in the insulating regime

Non-ohmicity and energy relaxation in diffusive 2D metals

We analyze current-voltage characteristics taken on Au-doped indium-oxide films. By fitting a scaling function to the data, we extract the electron-phonon scattering rate as function of temperature, which yields a quadratic dependence of the electron-phonon scattering rate on temperature from 1K down to 0.28K. The origin of this enhanced electron-phonon scattering rate is ascribed to the mechanism proposed by Sergeev and Mitin.Comment: 7 pages, 6 figure

Non-Ergodic Dynamics of an Electron Glass

We present the first experimental evidence for the existence of an electron glass. The glassy relaxation is monitored by time dependent conductance measurements following an excitation of electrons to conditions far from equilibrium. At low temperatures the samples exhibit memory-effects observable for hours, as is characteristic of glasses, demonstrating the existence of a glassy electronic phase. A simple model, based on the dynamics of non-interacting Anderson-localized electrons, is analyzed to show that dynamic constraints imposed by particle conservation alone can indeed exhibit the observed non-ergodic behavior

Forces Applied by Cilia Measured on Explants from Mucociliary Tissue

Forces applied by intact mucus-propelling cilia were measured for the first time that we know of using a combined atomic force microscopy (AFM) and electrooptic system. The AFM probe was dipped into a field of beating cilia and its time-dependent deflection was recorded as it was struck by the cilia while the electrooptic system simultaneously and colocally measured the frequency to ensure that no perturbation was induced by the AFM probe. Using cilia from frog esophagus, we measured forces of ∼0.21 nN per cilium during the effective stroke. This value, together with the known internal structure of these cilia, leads to the conclusion that most dynein arms along the length of the axoneme contribute to the effective stroke of these cilia