2,472 research outputs found
Examining Collegiality and Social Justice in Academia and the Private Sector: an Exploratory SYMLOG Analysis
This research compares the perceptions of the private sector, high-technology employees to the perceptions of university faculty members regarding organizational culture, social justice and collegiality concepts. The SYMLOG assessment technique was used to record the perceptions of respondents to four different concepts of organizational culture, two different aspects of social justice and two measures of collegiality. Comparative findings of gender differences across the eight concepts raise key organizational culture, legal, measurement, governance, and social policy issues for academia and high tech organizations. The development of a conceptual framework to guide future research and a blueprint to discuss desired organizational change are highlighted
Structure and spectroscopy of doped helium clusters using quantum Monte Carlo techniques
We present a comparative study of the rotational characteristics of various
molecule-doped 4He clusters using quantum Monte Carlo techniques. The
theoretical conclusions obtained from both zero and finite temperature Monte
Carlo studies confirm the presence of two different dynamical regimes that
correlate with the magnitude of the rotational constant of the molecule, i.e.,
fast or slow rotors. For a slow rotor, the effective rotational constant for
the molecule inside the helium droplet can be determined by a microscopic
two-fluid model in which helium densities computed by path integral Monte Carlo
are used as input, as well as by direct computation of excited energy levels.
For a faster rotor, the conditions for application of the two-fluid model for
dynamical analysis are usually not fulfilled and the direct determination of
excitation energies is then mandatory. Quantitative studies for three molecules
are summarized, showing in each case excellent agreement with experimental
results
Large-scale atomistic density functional theory calculations of phosphorus-doped silicon quantum bits
We present density functional theory calculations of phosphorus dopants in
bulk silicon and of several properties relating to their use as spin qubits for
quantum computation. Rather than a mixed pseudopotential or a Heitler-London
approach, we have used an explicit treatment for the phosphorus donor and
examined the detailed electronic structure of the system as a function of the
isotropic doping fraction, including lattice relaxation due to the presence of
the impurity. Doping electron densities and spin densities are examined in
order to study the properties of the dopant electron as a function of the
isotropic doping fraction. Doping potentials are also calculated for use in
calculations of the scattering cross-sections of the phosphorus dopants, which
are important in the understanding of electrically detected magnetic resonance
experiments. We find that the electron density around the dopant leads to
non-spherical features in the doping potentials, such as trigonal lobes in the
(001) plane at energy scales of +12 eV near the nucleus and of -700 meV
extending away from the dopants. These features are generally neglected in
effective mass theory and will affect the coupling between the donor electron
and the phosphorus nucleus. Our density functional calculations reveal detail
in the densities and potentials of the dopants which are not evident in
calculations that do not include explicit treatment of the phosphorus donor
atom and relaxation of the crystal lattice. These details can also be used to
parameterize tight-binding models for simulation of large-scale devices.Comment: 22 pages, 8 figure
Structure and energetics of helium adsorption on nanosurfaces
The ground and excited state properties of small helium clusters, 4He_N,
containing nanoscale (~3-10 Angstroms) planar aromatic molecules have been
studied with quantum Monte Carlo methods. Ground state structures and energies
are obtained from importance-sampled, rigid-body diffusion Monte Carlo. Excited
state energies due to helium vibrational motion are evaluated using the
projection operator, imaginary time spectral evolution technique. We examine
the adsorption of N helium atoms (N less than or equal to 24) on a series of
planar aromatic molecules (benzene, naphthalene, anthracene, tetracene,
phthalocyanine). The first layer of helium atoms is well-localized on the
molecule surface, and we find well-defined localized excitations due to
in-plane vibrational motion of helium on the molecule surface. We discuss the
implications of these confined excitations for the molecule spectroscopy.Comment: 6 pages, 2 figures, QFS 2003 Symposium, submitted to J. Low Temp.
Phy
Exact two-qubit universal quantum circuit
We provide an analytic way to implement any arbitrary two-qubit unitary
operation, given an entangling two-qubit gate together with local gates. This
is shown to provide explicit construction of a universal quantum circuit that
exactly simulates arbitrary two-qubit operations in SU(4). Each block in this
circuit is given in a closed form solution. We also provide a uniform upper
bound of the applications of the given entangling gates, and find that exactly
half of all the Controlled-Unitary gates satisfy the same upper bound as the
CNOT gate. These results allow for the efficient implementation of operations
in SU(4) required for both quantum computation and quantum simulation.Comment: 5 page
Snap-8 mercury corrosion and materials research, volume iii topical report, jun. 1960 - dec. 1962
SNAP-8 materials research - mercury corrosion capsule tests of ferritic alloys for mass transfer, stress corrosion, mode of attack, and mechanical propertie
Perfect initialization of a quantum computer of neutral atoms in an optical lattice of large lattice constant
We propose a scheme for the initialization of a quantum computer based on
neutral atoms trapped in an optical lattice with large lattice constant. Our
focus is the development of a compacting scheme to prepare a perfect optical
lattice of simple orthorhombic structure with unit occupancy. Compacting is
accomplished by sequential application of two types of operations: a flip
operator that changes the internal state of the atoms, and a shift operator
that moves them along the lattice principal axis. We propose physical
mechanisms for realization of these operations and we study the effects of
motional heating of the atoms. We carry out an analysis of the complexity of
the compacting scheme and show that it scales linearly with the number of
lattice sites per row of the lattice, thus showing good scaling behavior with
the size of the quantum computer.Comment: 18 page
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