Trapped ion emulation of electric dipole moment of neutral relativistic particles

The electric dipole moments of various neutral elementary particles, such as neutron, neutrinos, certain hypothetical dark matter particles and others, are predicted to exist by the standard model of high energy physics and various extensions of it. However, the predicted values are beyond the present experimental capabilities. We propose to simulate and emulate the electric dipole moment of neutral relativistic particles and the ensuing effects in the presence of electrostatic field by emulation of an extended Dirac equation in ion traps

Modeling of electroluminescence in InSb quantum wells and inversion asymmetric effects

The main focus of the dissertation is description, modeling and understanding of the mechanisms underpinning electroluminescence from quantum wells. The dissertation contains original contribution of methodological and phenomenological character. We have described in detail the eight band model within the envelope function approximation(EFA) using the Löwd in perturbation method used for band structure calculations. Although not novel, a detailed derivation of this is rarely done in the literature. We have derived a theoretical expression for electroluminescence spectral emittance based entirely on quantum mechanical model, unlike the more usual semi classical models used in semiconductor physics. The final expression for the spectral emittance has a different dependence compared to the semi classical expression, namely the prefactor in the newly derived expression is proportional to 2 . We use the combination of 8 band EFA method and the newly derived expression for spectral emittance to interpret experimental measurements on unpolarized spectral emittance from several InSb/AlxIn1-xSbquantum wells. We do that using slightly novel procedure and identify several transitions unreported in InSb/AlxIn1-xSb material system up to now. In simplified models these are regarded as forbidden. We show that in 8 band EFA model there aren’t any forbidden transitions. Instead all transitions are allowed and we discuss the product of momentum matrix elements and 2D density of states, to which we refer as "generalized selection rule", as the quantity which determines the strength of the individual transitions in different energy ranges. Furthermore we discuss three groups of mechanisms which determine various properties of the electroluminescence spectrum. These groups are entirely general to electroluminescence from all sorts of quantum wells. They are: (i) band structure embodied in the "generalized selection rules" ; (2) broadening effects and (3) statistical effects. Very important are the effects of structure inversion asymmetry (SIA) on the "generalized selection rules" and the spectral emittance, which we describe and explain. Finally we discuss aspects of two other major themes related to the two characteristic properties of InSb:(i) the broken space inversion invariance and (ii) the relativistic correction of spin-orbit coupling

Effects of Hydrophobic Gold Nanoparticles on Structure and Fluidity of SOPC Lipid Membranes

Gold nanoparticles (AuNPs) are promising candidates in various biomedical applications such as sensors, imaging, and cancer therapy. Understanding the influence of AuNPs on lipid membranes is important to assure their safety in the biological environment and to improve their scope in nanomedicine. In this regard, the present study aimed to analyze the effects of different concentrations (0.5, 1, and 2 wt.%) of dodecanethiol functionalized hydrophobic AuNPs on the structure and fluidity of zwitterionic 1-stearoyl-2-oleoyl-sn-glycerol-3-phosphocholine (SOPC) lipid bilayer membranes using Fourier-transform infrared (FTIR) spectroscopy and fluorescent spectroscopy. The size of AuNPs was found to be 2.2 ± 1.1 nm using transmission electron microscopy. FTIR results have shown that the AuNPs induced a slight shift in methylene stretching bands, while the band positions of carbonyl and phosphate group stretching were unaffected. Temperature-dependent fluorescent anisotropy measurements showed that the incorporation of AuNPs up to 2 wt.% did not affect the lipid order in membranes. Overall, these results indicate that the hydrophobic AuNPs in the studied concentration did not cause any significant alterations in the structure and membrane fluidity, which suggests the suitability of these particles to form liposome–AuNP hybrids for diverse biomedical applications including drug delivery and therapy