Bille Williamson (dragonscene0)

Semiconductor microcavities can greatly enhance the light-emitting of embedded quantum dots (QDs). Here, a new route toward the microcavity-QD system by fabricating microcavities followed by growing ordered QDs on patterned microresonator is proposed, which keeps QDs from being etched. Self-assembled Ge QDs prefer to form at the rims of Si microrings or microdisks. The Ge QDs on the pit- or groove-patterned microring resonator (MRR) show better size uniformity and position accuracy. These features are explained by the evolutions of surface morphology and surface chemical potential distribution. Sharp photoluminescence peaks in the telecommunication band with the quality factors in the range of 450-850 from groove-patterned MRR are observed at 295 K due to efficient overlap between Ge QDs and resonant modes. Our schemes shed light on the exactly site-controlled growth of QDs on micro- and nano-structures, which further facilitates the investigation of light-matter interactions.The temperature-dependent transversely isotropic elastic properties of multi-walled boron nitride nanotubes (MWBNNTs) were determined using molecular dynamics simulations with a three-body Tersoff potential force field. These elastic properties were calculated by applying the four different loading conditions on MWBNNTs uniaxial tension, torsional moment, in-plane biaxial tension and in-plane shear. The effect of chirality, number of layers and aspect ratio (AR) were taken into consideration. The results reveal that the elastic constants of MWBNNTs decrease as their number of layers increase. The elastic moduli of MWBNNTs do not depend on the AR but are function of chirality. selleck kinase inhibitor Furthermore, the effect of temperature on the transversely isotropic elastic constants of MWBNNTs was studied. The higher temperature considerably affects the mechanical properties of MWBNNTs. For instance, the reduction in the values of axial Young's, longitudinal shear, plane-strain bulk and in-plane shear moduli of MWBNNTs was found to be by approximately 10% due to the increase in temperature. The results reveal that the mechanical properties and failure behavior of MWBNNTs significantly depend on the number of layers, chirality and temperature. The finding of this work can be utilized for engineering the MWBNNT-based advanced nanocomposite structures for specific application under thermal environment.Unconventional lattice fermions with high degeneracies that are not Weyl or Dirac fermions have attracted increased attention in recent years. In this paper, we consider pseudospin-1 Maxwell fermions and the $(2+1)$-dimensional parity anomaly, which are not constrained by the fermion doubling theorem. We derive the Hall conductivity of a single Maxwell fermion and explain how each Maxwell fermion has a quantized Hall conductance of $e^2/h$. Parity is spontaneously broken in the effective theory of lattice Maxwell fermions interacting with an (auxiliary) U(1) gauge field, leading to an effective anomaly-induced Chern--Simons theory. An interesting observation about the parity anomaly is that the lattice Maxwell fermions are not constrained by the fermion doubling theorem, so a single Maxwell fermion can exist in a lattice. In addition, our work considers the quantum anomaly in odd-dimensional spinor space.The concept of realization of Weyl points close to Fermi level in materials with broken time-reversal symmetry has significant theoretical and technological ramifications. Here, we review on the investigation of magneto-transport measurements in single crystals of magnetic Weyl semimetal Co3Sn2S2. We see a turn-on like behaviour followed by saturation in resistivity under magnetic field in the low temperature region which allocates to the topological surface states. A non-saturating magnetoresistance, linear at high fields, is observed at low temperatures where applied magnetic field is transverse to the current direction. The linear negative magnetoresi