11,177 research outputs found
Jamming, relaxation and crystallization of a super-cooled fluid in a three-dimensional lattice
Off-equilibrium dynamics of a three-dimensional lattice model with nearest-
and next nearest-neighbors exclusions is studied. At equilibrium, the model
undergoes a first-order fluid-solid transition. Non-equilibrium filling,
through random sequential adsorption with diffusion, creates amorphous
structures and terminates at a disordered state with random closest packing
density that lies in the equilibrium solid regime. The approach towards random
closest packing is characterized by two distinct power-law regimes, reflecting
the formation of small densely packed grains in the long time regime of the
filling process. We then study the fixed-density relaxation of these amorphous
structures towards the solid phase. The route to crystallization is shown to
deviate from the simple grain growth proposed by classical nucleation theory.
Our measurements suggest that relaxation is driven mainly by coalescence of
neighboring crystallized grains which exist in the initial amorphous state
Process techniques study of integrated circuits Interim scientific report, May 1968 - Feb. 1969
Oxide defects and shear stress effects in integrated circuit
Ground State Spin Structure of Strongly Interacting Disordered 1D Hubbard Model
We study the influence of on-site disorder on the magnetic properties of the
ground state of the infinite U 1D Hubbard model. We find that the ground state
is not ferromagnetic. This is analyzed in terms of the algebraic structure of
the spin dependence of the Hamiltonian. A simple explanation is derived for the
1/N periodicity in the persistent current for this model.Comment: 3 pages, no figure
Photodisintegration of light nuclei for testing a correlated realistic interaction in the continuum
An exact calculation of the photodisintegration cross section of 3H, 3He and
4He is performed using as interaction the correlated Argonne V18 potential,
constructed within the Unitary Correlation Operator Method (VUCOM).
Calculations are carried out using the
Lorentz Integral Transform method in conjunction with an hyperspherical
harmonics basis expansion. A comparison with other realistic potentials and
with available experimental data is discussed. The VUCOM potential leads to a
very similar description of the cross section as the Argonne V18 interaction
with the inclusion of the Urbana IX three-body force for photon energies 45< w
< 120 MeV, while larger differences are found close to threshold.Comment: 9 pages, 6 figure
Hindrance of heavy-ion fusion due to nuclear incompressibility
We propose a new mechanism to explain the unexpected steep falloff of fusion
cross sections at energies far below the Coulomb barrier. The saturation
properties of nuclear matter are causing a hindrance to large overlap of the
reacting nuclei and consequently a sensitive change of the nuclear potential
inside the barrier. We report in this letter a good agreement with the data of
coupled-channels calculation for the {64}Ni+{64}Ni combination using the
double-folding potential with M3Y-Reid effective N-N forces supplemented with a
repulsive core that reproduces the nuclear incompressibility for total overlap.Comment: 4 pages, 3 figure
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