Computer study of nonequilibrium excitation in recombining nitrogen plasma nozzle flows

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77276/1/AIAA-1970-44-576.pd

Quasi-particle scattering and protected nature of topological states in a parent topological insulator Bi2_2Se3_3

We report on angle resolved photoemission spectroscopic studies on a parent topological insulator (TI), Bi$_2$Se$_3$. The line width of the spectral function (inverse of the quasi-particle lifetime) of the topological metallic (TM) states shows an anomalous behavior. This behavior can be reasonably accounted for by assuming decay of the quasi-particles predominantly into bulk electronic states through electron-electron interaction and defect scattering. Studies on aged surfaces reveal that topological metallic states are very much unaffected by the potentials created by adsorbed atoms or molecules on the surface, indicating that topological states could be indeed protected against weak perturbations.Comment: accepted for publication in Phys. Rev. B(R

Schottky nanocontacts on ZnO nanorod arrays

We report on fabrication and electrical characteristics of ZnO nanorod Schottky diode arrays. High quality ZnO nanorods were grown for the fabrication of the Schottky diodes using noncatalytic metalorganic vapor phase epitaxy and Au was evaporated on the tips of the vertically well-aligned ZnO nanorods. I-V characteristics of both bare ZnO and Au/ZnO heterostructure nanorod arrays were measured using current-sensing atomic force microscopy. Although both nanorods exhibited nonlinear and asymmetric I-V characteristic curves, Au/ZnO heterostructure nanorods demonstrated much improved electrical characteristics: the reverse-bias breakdown voltage was improved from -3 to -8 V by capping a Au layer on the nanorod tips. The origin of the enhanced electrical characteristics for the heterostructure nanorods is suggested. (C) 2003 American Institute of Physics

The false vacuum bubble nucleation due to a nonminimally coupled scalar field

We study the possibility of forming the false vacuum bubble nucleated within the true vacuum background via the true-to-false vacuum phase transition in curved spacetime. We consider a semiclassical Euclidean bubble in the Einstein theory of gravity with a nonminimally coupled scalar field. In this paper we present the numerical computations as well as the approximate analytical computations. We mention the evolution of the false vacuum bubble after nucleation.Comment: 23 pages, 12 figures, References added, minor correctio

Metalorganic vapor-phase epitaxial growth and photoluminescent properties of Zn1-xMgxO (0 < x < 0.47) thin films

High-quality Zn1-xMgxO(0.00 less than or equal tox less than or equal to0.49) thin films were epitaxially grown at 500-650 degreesC on Al2O3(00.1) substrates using metalorganic vapor-phase epitaxy. By increasing the Mg content in the films up to 49 at. %, the c-axis constant of the films decreased from 5.21 to 5.14 Angstrom and no significant phase separation was observed as determined by x-ray diffraction measurements. Furthermore, the near-band-edge emission peak position showed blueshifts of 100, 440, and 685 meV at Mg content levels of 9, 29, and 49 at. %, respectively. Photoluminescent properties of the alloy films are also discussed.This research was sponsored by the KISTEP through the National Research Laboratory program, the Brain Korea 21 project, and the POSTECH BSRI Special Fund-2001

Flavor structure of the octet magnetic moments

We use the chiral quark-soliton model to identify all symmetry breaking terms linear in $m_{s}$ and investigate the strange magnetic moment in a ``model-independent'' way. Assuming hedgehog symmetry and employing the collective quantization, we obtain the most general expression for the flavor-singlet and flavor-octet magnetic moments in terms of seven independent parameters. Having fitted these parameters to the experimental magnetic moments of the octet baryons, we show that the strange magnetic moment turns out to be positive. The best fit obtained by minimizing $\chi^2$ assuming 15% theoretical accuracy yields: $\mu^{({\rm s})}_{N} = (0.41 \pm 0.18) \mu_{N}$.Comment: 10 pages. RevTeX is used. One figure is included. The final version accepted for publication in Phys. Rev.