Transient velocity overshoot dynamics in GaAs for electric fields ≤ 200 kV/cm

Transient velocity overshoot dynamics *in GaAs for electric fields

We have experimentally studied the transient velocity overshoot dynamics of photoexcited carriers in GaAs for electric fields as great as 200 kV/cm. Time domain waveforms proportional to the velocity and the acceleration of carriers have been acquired? respectively, from guided and free-space radiating signals which contain terahertz frequency components. The measurements demonstrated that the ...

Velocity modulation of microtubules in electric fields.

We show that the speed of microtubules gliding over a kinesin-coated surface can be controlled over a wide range of values by the application of an electric field. The speed can be increased by up to a factor of 5 compared to the speed at zero field when assisting forces are applied and slowed down to zero velocity for opposing fields. Sideways applied fields also induce significant motion. The...

Electric fields associated with transient surface currents

Dynamics of electric field screening in a bulk GaAs modulator.

The transient development of electric-field distributions in a biased GaAs film after low density optical excitation is determined by measurements of Franz-Keldysh modulations with a time resolution of 100 fs. The experimental results are compared with theoretical calculations. The transient field is calculated with a drift-diffusion model. Our calculation of the dielectric function of GaAs inc...

Electric charge separation in strong transient magnetic fields

We discuss various mechanisms for the creation of an asymmetric charge fluctuation with respect to the reaction plane among hadrons emitted in relativistic heavy-ion collisions. We show that such mechanisms exist in both the hadronic gas and the partonic phases of quantum chromodynamics. The mechanisms considered here all require the presence of a strong magnetic field (the “chiral magnetic eff...