Scanning tunneling electroluminescence (STL) microscopy is performed on a 3 nm-thick InGaN/GaN quantum well (QW) with [In] = 0.23 such that the main light emission occurs in green. The technique used to map radiative recombination properties at scale of few nanometers and correlate local surface topography simultaneously imaged by scanning microscopy. While expected green observed all over samp...

we prove that the class of profinite groups $g$ that have a factorization $g=ab$ with $a$ and $b$ abelian closed subgroups, is closed under taking strict projective limits. this is a generalization of a recent result by k.h.~hofmann and f.g.~russo. as an application we reprove their generalization of iwasawa's structure theorem for quasihamiltonian pro-$p$ groups.

We present the results of a twofold experimental and computational study (0001) GaN/AlN multilayers forming pseudomorphic superlattices. High-Resolution Transmission Electron Microscopy (HRTEM) shows that heterostructures with four c-lattice parameters thick GaN Quantum Wells (QW) are misfit-dislocation free. Accurate structural data extracted from HRTEM images via new methodology optimizing re...

We discuss general relativistic effects in the steady state neutrino-driven “wind” that may arise from nascent neutron stars. In particular, we generalize previous analytic estimates of the entropy per baryon S, the mass outflow rate Ṁ, and the dynamical expansion timescale tdyn. We show that S increases and tdyn decreases with increasing values of the mass-to-radius ratio describing the supern...

By varying two design parameters, e.g., the width of a quantum well (QW) and its chemical composition, or by applying an external field, it is possible to implement two QW's with identical ground-state levels in the conduction band but different in the valence band. This allows a selective "preparation" of an initial electron state by interband photoexcitation. In a coupled QW system the electr...

We consider a two-dimensional magnetic tunnel junction of the FM/I/QW(FM+SO)/I/N structure, where FM, I and QW(FM+SO) stand for a ferromagnet, an insulator and a quantum wire with both magnetic ordering and Rashba spin-orbit (SOC), respectively. The tunneling magneto-resistance (TMR) exhibits strong anisotropy and switches sign as the polarization direction varies relative to the quantum-wire a...

The phase diagram of the two-leg Kondo ladder is investigated using computational techniques. Ferromagnetism is present, but only at small conduction electron densities and robust Kondo coupling J. For densities n*0.4 and any Kondo coupling, a paramagnetic phase is found. We also observed spin dimerization at densities n=1/4 and n=1/2. The spin-structure factor at small J peaks at qW = s2n ,0dp...

We investigated the high-carrier screening of macroscopic polarization fields in GaN quantum wells (QWs) using a variational wave function for electrons and holes. In particular, we studied of the influence of free-carrier screening on the photoluminescence (PL) energy emission and carrier lifetime in the QW. We show that the energy transition between electrons and holes are explained well by t...