58 research outputs found
Hubbard-U calculations for Cu from first-principles Wannier functions
We present first-principles calculations of optimally localized Wannier
functions for Cu and use these for an ab-initio determination of Hubbard
(Coulomb) matrix elements. We use a standard linearized muffin-tin orbital
calculation in the atomic-sphere approximation (LMTO-ASA) to calculate Bloch
functions, and from these determine maximally localized Wannier functions using
a method proposed by Marzari and Vanderbilt. The resulting functions were
highly localized, with greater than 89% of the norm of the function within the
central site for the occupied Wannier states. Two methods for calculating
Coulomb matrix elements from Wannier functions are presented and applied to fcc
Cu. For the unscreened on-site Hubbard for the Cu 3d-bands we have obtained
about 25eV. These results are also compared with results obtained from a
constrained local-density approximation (LDA) calculation.Comment: 13 pages, 8 figures, 5 table
Use Of A Surface-emitting Micro-laser Array For Optical Computing
Surface emitting microlaser arrays have many features that make them highly desirable for use in optical computing. In this talk, we will describe various applications of the novel device for optical computing, with emphasis on ,neural network implementations
Use Of A Surface-emitting Micro-laser Array For Optical Computing
Surface emitting microlaser arrays have many features that make them highly desirable for use in optical computing. In this talk, we will describe various applications of the novel device for optical computing, with emphasis on ,neural network implementations
A New Learning Algorithm for Neural Networks with Integer Weights and Quantized Non-linear Activation Functions
Saturation of Band-Tail Absorption in Multiple Quantum Wells and Its Link with the Nonlinear Index Saturation
Compact and robust incoherent holographic correlator using a surface-emitting laser-diode array
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