Related papers: Underlying Physical Mechanisms in Upward Positive …

This study examines the relationship between upward negative stepped leader pulses in upward positive lightning and preliminary breakdown pulses (PBPs) in downward negative lightning discharges. Through analysis of simultaneous channel-base…

X-rays have been observed in natural downward cloud-to-ground lightning for over twenty years and in rocket-triggered lightning for slightly less. In both cases, this energetic radiation has been detected during the stepped and dart leader…

Upward lightning is much rarer than downward lightning and requires tall ($100+$~m) structures to initiate. It may be either triggered by other lightning discharges or completely self-initiated. While conventional lightning location systems…

We show that, in a magnetic field parallel to the 2D electron layer, strong electron correlations change the rate of tunneling from the layer exponentially. It results in a specific density dependence of the escape rate. The mechanism is a…

A model for charge transport in undoped, photo-excited semiconductor superlattices, which includes the dependence of the electron-hole recombination on the electric field and on the photo-excitation intensity through the field-dependent…

Where particle acceleration and plasma heating take place in relation to magnetic reconnection is a fundamental question for solar flares. We report analysis of an M7.7 flare on 2012 July 19 observed by SDO/AIA and RHESSI. Bi-directional…

Combining experiments and computer simulations, we use a spatially periodic and flashing light-field to direct the motion of phototactic active colloids. Here, the colloids self-organize into a density spike pattern, which resembles a shock…

Between May and October 2013 (period of sustained thunderstorm activity in France), several cloud-to-ground lightning flashes have been observed in Paris area with a high-speed video camera (14000 frames per second). The localization and…

It is well known that magnetic fields constrain motions of charged particles, impeding the diffusion of charged particles perpendicular to magnetic field direction. This modification of transport processes is of vital importance for a wide…

Phase transitions are ubiquitous, appearing at every length scale from atoms to galaxies. In condensed matter, ultrafast laser pulses drive materials to highly non-equilibrium conditions allowing transitions to new phases of matter not…

Electric currents circulating between charged clouds and the earth surface during lightning discharges are responsible for considerable damages and casualties. It is therefore important to develop better protection methods in addition to…

In order to ensure the fastest wireless energy transfer from a source to the user one needs to maximize the channel capacity for power transport. In communications technologies, the concept of MIMO (multiple input, multiple output) exploits…

We observe the buildup of a frequency-shifted reverse light field in a unidirectionally pumped high-$Q$ optical ring cavity serving as a dipole trap for cold atoms. This effect is enhanced and a steady state is reached, if via an optical…

Transitional millisecond pulsars are an emerging class of sources that link low-mass X-ray binaries to millisecond radio pulsars in binary systems. These pulsars alternate between a radio pulsar state and an active low-luminosity X-ray disc…

With LOFAR we have been able to image the development of lightning flashes with meter-scale accuracy and unprecedented detail. We discuss the primary steps behind our most recent lightning mapping method. To demonstrate the capabilities of…

A high-intensity laser pulse propagating through a medium triggers an ionization front that can accelerate and frequency-upshift the photons of a second pulse. The maximum upshift is ultimately limited by the accelerated photons outpacing…

We carry out experiments on single-molecule junctions at low temperatures, using the mechanically controlled break junction technique. Analyzing the results received with more than ten different molecules the nature of the first peak in the…

We have investigated charge transport in ultrasmall superconducting single and double Josephson junctions coupled to resonant modes of the electromagnetic environment. We observe pronounced current peaks in the transport characteristics of…

We propose a new two-stage model for acceleration of electrons in solar flares. In the first stage, electrons are accelerated stochastically in a post-reconnection turbulent downflow. The second stage is the reprocessing of a subset of…

The transition between different states in manganites can be driven by various external stimuli. Controlling these transitions with light opens the possibility to investigate the microscopic path through which they evolve. We performed…