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We calculate the phase property of the reflection coefficient in two-terminal structures using a lattice tight-binding model. It is seen that, provided that there exist two coherent reflection paths, the reflection probability can be zero for certain electron energies. At these energies, the phase of the reflection coefficient shift abruptly by $pi$. Next, we study the reflection and transmissio

Fundamental symmetries in thermoelectric quantum transport, beyond Onsagers relations, were predicted two decades ago but have to date not been observed in experiments. Recent works have predicted the symmetries to be sensitive to energy-dependent, inelastic scattering, raising the question whether they exist in practice. Here, we answer this question affirmatively by experimentally verifying the

In semiconductor nanocrystals, called quantum dots (QD), electronic transition energies, phonon frequencies, and electron-phonon coupling strengths are all reported to depend on the size of the crystals. The size dependencies of the transition energies and the mode frequencies are well characterized and understood. At the same time, the electron-phonon coupling dependence on size is controversial-

We consider an autonomous implementation of Maxwell's demon in a quantum dot architecture acting on a system without changing its number of particles or its energy. As in the original thought experiment, only the second law of thermodynamics is seemingly violated when disregarding the demon. The autonomous architecture allows us to compare descriptions in terms of information to a more traditional

Different screening models in quantum cascade lasers are compared by calculating the contribution of intrasubband impurity scattering to the optical linewidth as a function of temperature. We find a strong impact of impurity scattering, which increases substantially with temperature. A simple isotropic bulk screening model works well if the screening length is of the order of or longer than the pe

heory predicts that electrons emitted from independent electron sources (metallic contacts) can nevertheless interfere. This interference is manifest in an exchange contribution to the shot noise correlation of currents at different contacts of a mesoscopic conductor. A geometry has been proposed in which second order (single particle) interference due to superposition of amplitudes is absent but

The theory of nonequilibrium Green functions allows for a quantitative modeling of quantum cascade lasers. Explicit results are given for transport in a THz-laser and gain in a IR-Laser

Abstract: We study oscillations in quantum cascade lasers due to traveling electric field domains, which are observed both in simulations and experiments. These oscillations occur in a range of negative differential resistance and we clarify the condition determining whether the boundary between domains of different electric field can become stationary. Graphical abstract: [Figure not available: s

We show that mid-infrared transmission spectroscopy of a quantum cascade laser provides clear-cut information on changes in charge location at different bias. Theoretical simulations of the evolution of the gain/absorption spectrum for a lambda~7.4 µm InGaAs/AlInAs/InP quantum cascade laser have been compared with the experimental findings. Transfer of electrons between the ground states in the ac

In particle collider experiments, elementary particle interactions with large momentum transfer produce quarks and gluons (known as partons) whose evolution is governed by the strong force, as described by the theory of quantum chromodynamics (QCD)1. These partons subsequently emit further partons in a process that can be described as a parton shower2, which culminates in the formation of detectab

The downscaling of silicon-based structures and proto-devices has now reached the single-atom scale, representing an important milestone for the development of a silicon-based quantum computer. One especially notable platform for atomic-scale device fabrication is the so-called Si:P δ-layer, consisting of an ultra-dense and sharp layer of dopants within a semiconductor host. Whilst several alterna

A review of recent research, as well as new results, are presented on transition metal oxide clusters, surfaces, and crystals. Quantum-chem. calcns. of clusters of first row transition metal oxides have been made to evaluate the accuracy of ab initio and d. functional calcns. Adsorbates on metal oxide surfaces have been studied with both ab initio and semi-empirical methods, and results are presen