Thermoelectric transport in semiconductors is usually considered under small thermal gradients and when it is dominated by the role of the majority carriers. Not much is known about effects that arise under the large thermal gradients that can be established in high-temperature, small-scale electronic devices. Here, we report a surprisingly large asymmetry in self-heating of symmetric highly do...

We investigated the low-temperature transport mechanism for poly[2,5-bis(3-alkylthiophen-2-yl)thieno(3,2-b)thiophene] (PBTTT). The temperature-dependent transport behavior was studied by varying the drain-source electric field and gate bias. The results suggest that low-temperature charge transport is dominated by direct tunneling at low electric fields, while field emission is prevailing for h...

In this paper we examine the issue of characterising the transport associated with gravitational instabilities in relatively cold discs, discussing in particular the conditions under which it can be described within a local, viscous framework. We present the results of global, three-dimensional, SPH simulations of self-gravitating accretion discs, in which the disc is cooled using a simple para...

Improvements in our understanding of transport processes in the stratosphere have progressed hand in hand with advances in understanding of stratospheric dynamics and with accumulating remote and in situ observations of the distributions of, and relationships between, stratospheric tracers. It is convenient to regard the stratosphere as being separated into four regions: the summer hemisphere, ...

Spintronics devices rely on spin-dependent transport behavior evoked by the presence of spin-polarized electrons. Transport through nanostructures, on the other hand, is dominated by strong Coulomb interaction. We study a model system in the intersection of both fields, a quantum dot attached to ferromagnetic leads. The combination of spin-polarization in the leads and strong Coulomb interactio...

Nanoscale thermal transport has attracted considerable attention because of both fundamental scientific interest and important engineering applications. For semiconductors and insulators, energy transport is dominated by phonons, whose behavior at surfaces and interfaces plays a significant role in energy transport processes. In this article, we present opinions on phonon dynamics at surfaces a...

The mechanisms for anomalous transport across the magnetic field are investigated in a toroidal magnetized plasma. The role of plasma instabilities and macroscopic density structures (blobs) is discussed. Examples from a scenario with open magnetic field lines are shown. A transition from a main plasma region into a loss region is reproduced. In the main plasma, which includes particle and heat...

Recent measurements of the strength of the Atlantic overturning circulation at 26∘N show a 1 year drop and partial recovery amid a gradual weakening. To examine the extent and impact of the slowdown on basin wide heat and freshwater transports for 2004–2012, a box model that assimilates hydrographic and satellite observations is used to estimate heat transport and freshwater convergence as resi...

The most common solutions to the light transport problem rely on either Monte Carlo (MC) integration or density estimation methods, such as uni& bi-directional path tracing or photon mapping. Recent gradient-domain extensions of MC approaches show great promise; here, gradients of the final image are estimated numerically (instead of the image intensities themselves) with coherent paths generat...

A density matrix approach is used in combination with a tight-binding model to describe electron transport in terahertz quantum cascade lasers and is incorporated into a Monte Carlo simulation. Scattering events, including LO-phonon, electron-electron, and ionized impurity scattering, are treated semiclassically but contribute to dephasing scattering. In addition, a phenomenological “pure depha...