16 research outputs found
Polarized Single Top Quark Production in e\gamma Collision and Anomalous Wtb Couplings
We investigate the potential of collisions to probe anomalous
couplings via the polarized single top quark production process . We find 95% confidence level limits on the
anomalous coupling parameters and with an integrated
luminosity of and and 1.5 TeV energies. The
effects of top quark spin polarization on the anomalous couplings are
discussed. It is shown that polarization leads to a considerable improvement in
the sensitivity limits.Comment: published versio
Empirical tight binding parameters for GaAs and MgO with explicit basis through DFT mapping
The Empirical Tight Binding (ETB) method is widely used in atomistic device simulations. The reliability of such simulations depends very strongly on the choice of basis sets and the ETB parameters. The traditional way of obtaining the ETB parameters is by fitting to experiment data, or critical theoretical bandedges and symmetries rather than a foundational mapping. A further shortcoming of traditional ETB is the lack of an explicit basis. In this work, a DFT mapping process which constructs TB parameters and explicit basis from DFT calculations is developed. The method is applied to two materials: GaAs and MgO. Compared with the existing TB parameters, the GaAs parameters by DFT mapping show better agreement with the DFT results in bulk band structure calculations and lead to different indirect valleys when applied to nanowire calculations. The MgO TB parameters and TB basis functions are also obtained through the DFT mapping process