Sökresultat

The electronic properties of quantum dot (QD) arrays are strongly influenced by the Coulomb interaction of electrons within the dot as well as with those in neighbouring dots. In this paper, we investigate this behaviour taking into account screening by a free electron gas in the vicinity of the QDs. We find pronounced effects for standard capacitance - voltage ( CV) measurements of QD structures

High-order Harmonic Generation (HHG) is a highly non-linear process in which an atom interacts with a strong laser field. The laser field lowers the atomic potential barrier allowing bound electrons to escape into the continuum through tunnel ionization, propagate, and, with some probability, recombine with the parent ion. As a result, coherent eXtreme UltraViolet (XUV) radiation is emitted in the

In the present study, entropy generation in rectangular cavities with the same area but different aspect ratios is numerically investigated. The vertical walls of the cavities are at different constant temperatures while the horizontal walls are adiabatic. Heat transfer between vertical walls occurs by laminar natural convection. Based on the obtained dimensionless velocity and temperature values,

We present a theory for a mesoscopic turnstile that produces spatially separated streams of electrons and holes along edge states in the quantum Hall regime. For a broad range of frequencies in the nonadiabatic regime the turnstile operation is found to be ideal, producing one electron and one hole per cycle. The accuracy of the turnstile operation is characterized by the fluctuations of the trans

We investigate shot noise of photon-excited electron-hole pairs in open multiterminal, multichannel chaotic dots. Coulomb interactions in the dot are treated self-consistently giving a gauge-invariant expression for the finite frequency correlations. The Coulomb interactions decrease the noise; the strong interaction limit coincides with the noninteracting adiabatic limit. Inelastic scattering and

We experimentally verify hitherto untested theoretical predictions about the thermoelectric properties of Kondo correlated quantum dots (QDs). The specific conditions required for this study are obtained by using QDs epitaxially grown in nanowires, combined with a recently developed method for controlling and measuring temperature differences at the nanoscale. This makes it possible to obtain data

In classical thermodynamics energy always flows from the hotter system to the colder one. However, if these systems are initially correlated, the energy flow can reverse, making the cold system colder and the hot system hotter. This intriguing phenomenon is called "anomalous energy flow"and shows the importance of initial correlations in determining physical properties of thermodynamic systems. He

We demonstrate a novel dispersion-scan (d-scan) scheme for single-shot temporal characterization of ultrashort laser pulses. The novelty of this method relies on the use of a highly dispersive crystal featuring antiparallel nonlinear domains with a random distribution and size. This crystal, capable of generating a transverse second-harmonic signal, acts simultaneously as the dispersive element an

In the Peyer's patches (PPs), germinal centers (GCs) are chronically induced by bacteria and are the major sites for generation of gut immunoglobulin A (IgA) immune responses. Whether follicular dendritic cells (FDCs) within the GCs directly contribute to the IgA production in PPs is unknown. We showed here that direct stimulation of FDCs by bacterial products and retinoic acid synergistically enh

https://www.lu.se/evenemang/body-and-emotions-spectacle-borders - 2026-10-08

Med ett av världens starkaste och skarpaste ljus ... ... kan forskare vid MAX IV i Lund se det som är osynligt för det mänskliga ögat. Exakt hur det går till är svårt att förklara – även för många av dem som besökt anläggningen. Ändå påverkar forskningen oss alla, från kartongen som vi häller mjölk ur till vilka läkemedel som kommer att finnas i framtiden. – Att kunna se exakt hur läkemedlen funge

https://www.lu.se/max-iv-konkurrenskraften-borjar-pa-atomniva - 2026-10-08

Swedish parents today raise their children in a welfare state, where childcare is both accessible and affordable, and often within dual-income households. At the same time, they have witnessed a challenged welfare state affected by cutbacks, privatizations, and the demands of an increasingly flexible working life. Previous research has shown that Swedish grandparents are more involved in their aduSwedish parents today raise their children in a welfare state, where childcare is both accessible and affordable, and often within dual-income households. At the same time, they have witnessed a challenged welfare state affected by cutbacks, privatizations, and the demands of an increasingly flexible working life. Previous research has shown that Swedish grandparents are more involved in their adu

https://www.lu.se/studera/fysik-kvantmekanik-FYSN27 - 2026-10-09

A misaligned stretcher or compressor in a chirped pulse amplification laser introduces residual angular dispersion into the beam, resulting in temporal distortion of the pulse. We demonstrate that an imaging spectrograph is capable for Measuring the angular dispersion of a laser beam by an accuracy of 0.2 murad/min. Using this technique, the analytical expressions of residual angular dispersion of

Interactions between physical bodies constantly affect their properties. This thesis presents a theoretical study on the effects of interaction in few-body nanowire quantum dots. The focus is to a large extent on a phenomenon called Wigner localization, and how this, as well as other interaction effects, can be identified in an experiment by transport spectroscopy and by thermopower measurements.

Ultra-violet angle-resolved photoemission spectroscopy (UV-ARPES) was used to explore the temperature dependence of the Ce-4f spectral responses for surface and bulk in the antiferromagnetic Kondo lattice CeRh2Si2. Spectra were taken from Ce- and Si-terminated surfaces in a wide temperature range, and reveal characteristic 4f patterns for weakly (surface) and strongly (bulk) hybridized Ce, respect