A new method to extract gate coupling ratio and oxide trapped charge in flash memory cell

A new method to obtain the gate coupling ratio (α_g) and oxide trapped charge (Q_ox) as a result of cycling in flash memory cells is described here. Three cells with an equivalent physical structure but different erase characteristics are measured. The threshold changes versus erase times are fitted to the charge removal rate calculated based on Fowler-Nordheim (FN) tunneling and the capacitive relations among all nodes. The extracted α_g is independent of technologies and this method is particular useful when the profile of the floating gate is not traditionally rectangular owing to advanced processes such as trapezoidal poly etch or a poly-spacer addition on the floating gate sidewall. The Q_ox can also be determined once α_g is extracted.     

Pauli exchange effects in the elastic scattering of O + O

The real optical potential for ¹⁶O+¹⁶O system is calculated within a generalized version of the double-folding model with the Pauli knock-on exchange effects between the projectile nucleons and the target nucleons taken into account from first principle. The elastic scattering data at E_lab=350 MeV supplemented by the new measurement at larger angles seem to be the first case in heavy-ion scattering where one can test the reliability of different theoretical heavy-ion optical potentials. Predictions are made for the elastic scattering of ¹⁶O+¹⁶O at laboratory energies of 240–480 MeV to illustrare the energy dependence of the rainbow structure which has been clearly observed in experiment at 350 MeV.     

Exciton-exciton interaction in quantum wells

Il Nuovo Cimento D - Fast initial decays of both the luminescence intensity and the circular luminescence polarization at high exciton densities, under resonant excitation, are reported for the...     

Validated design of dynamic membership services and protocols for cooperative groups

This paper first presents a groupware service and an associated protocol that manage the dynamic membership of agents inside cooperative groups and second gives the design methodology that has been used for defining the service and the protocol. The model used to represent cooperative groups is based on graphs that give the knowledge relationships between agents and define the dynamics of the group. The protocol providing the membership service is specified using the VAL formal specification environment based on a Petri net formalism. The VAL specification is verified using observational and safety projections derived from the reachability graph. Then the VAL specification is translated and adapted to an Estelle specification. The Estelle specification has been used for a final implementation of the protocol on top of a distributed platform.     

Polarization of α-clusters in light nuclei?

The α-particle model of Brink is extended to allow for non-spherical clusters. This is done by admixingp-functions to thes-single particle states which represent, in the usual version of the model, the nucleons in a cluster. The results in the nuclei⁸Be,¹²C,¹⁶O, and²⁰Ne indicate that the spherical clusters represent the stable configurations.     

g Factors for high-spin states of238U

Calculations of the g-factor and the moment of inertia J for high-spin states of²³⁸U are performed using the model which is based on the cranking Hartree-Fock-Bogolyubov (CHFB) theory. Importance of the state-dependent pairing force on 3(ω²) is investigated.     

Multi-configuration Hartree-Fock theory in nuclei

A variational method for the self-consistent solution of the nuclear many body problem with the inclusion of correlations is formulated. The trial function in this multiconfiguration-Hartree-Fock (MCHF) theory is a linear combination of unrestricted Slater determinants. The MCHF equations are given and a simple procedure for solving them is outlined. A great advantage of this method is that it also yields the excited states. It is shown that the trial function is stable against particle-hole excitations. Therefore the Slater determinants differ from each other at least by two particle — two hole excitations. This method is applied to the Lipkin model. In the MCHF method the difference to the exact solution is reduced by a factor three to ten compared with the corresponding value in the HF approach.     

High spin states and pairing vibrations

The Generator-Coordinate-Method is applied to describe yrast-bands and excited vibrational bands of pairing-vibrational orβ-vibrational type in deformed rare earth nuclei. The model wave functions are supplied by the Pairing+Quadrupole-Model with angular momentum — and particle number projection. Results are shown for the nucleus¹⁷⁰Yb. The question if backbending may be produced by the intersection of the ground and the neutron pairing vibrational band is discussed.