Impact of random dopant induced fluctuations on sub-15nm UTB SOI 6T SRAM cells

The CMOS scaling increases the impact of intrinsic parameter fluctuation on the yield and functionality of SRAM. A statistical circuit simulation framework which can fully capture intrinsic parameter fluctuation information into the compact model has been developed. The impact of discrete random dopants in the source and drain regions on 6T SRAM cells has been investigated for well scaled ultra thin body (UTB) SOI MOSFETs with physical channel length in the range of 10nm to 5nm

UTB SOI SRAM cell stability under the influence of intrinsic parameter fluctuation

Intrinsic parameter fluctuations steadily increases with CMOS technology scaling. Around the 90nm technology node, such fluctuations will eliminate much of the available noise margin in SRAM based on conventional MOSFETs. Ultra thin body (UTB) SOI MOSFETs are expected to replace conventional MOSFETs for integrated memory applications due to superior electrostatic integrity and better resistant to some of the sources of intrinsic parameter fluctuations. To fully realise the performance benefits of UTB SOI based SRAM cells a statistical circuit simulation methodology which can fully capture intrinsic parameter fluctuation information into the compact model is developed. The impact on 6T SRAM static noise margin characteristics of discrete random dopants in the source/drain regions and body-thickness variations has been investigated for well scaled devices with physical channel length in the range of 10nm to 5nm. A comparison with the behaviour of a 6T SRAM based on a conventional 35nm MOSFET is also presented

Cross-section and polarization of neutrino-produced τ\tau's made simple

Practical formulae are derived for the cross-section and polarization of the $\tau$ lepton produced in deep-inelastic neutrino-nucleon scattering in the frame of the simple quark-parton model.Comment: 10 pages, no figure

Self-management of context-aware overlay ambient networks

Ambient Networks (ANs) are dynamically changing and heterogeneous as they consist of potentially large numbers of independent, heterogeneous mobile nodes, with spontaneous topologies that can logically interact with each other to share a common control space, known as the Ambient Control Space. ANs are also flexible i.e. they can compose and decompose dynamically and automatically, for supporting the deployment of cross-domain (new) services. Thus, the AN architecture must be sophisticatedly designed to support such high level of dynamicity, heterogeneity and flexibility. We advocate the use of service specific overlay networks in ANs, that are created on-demand according to specific service requirements, to deliver, and to automatically adapt services to the dynamically changing user and network context. This paper presents a self-management approach to create, configure, adapt, contextualise, and finally teardown service specific overlay networks

Matter-wave localization in a random potential

By numerical and variational solution of the Gross-Pitaevskii equation, we studied the localization of a noninteracting and weakly-interacting Bose-Einstein condensate (BEC) in a disordered cold atom lattice and a speckle potential. In the case of a single BEC fragment, the variational analysis produced good results. For a weakly disordered potential, the localized BECs are found to have an exponential tail as in weak Anderson localization. We also investigated the expansion of a noninteracting BEC in these potential. We find that the BEC will be locked in an appropriate localized state after an initial expansion and will execute breathing oscillation around a mean shape when a BEC at equilibrium in a harmonic trap is suddenly released into a disorder potential

Vacuum ultraviolet photoabsorption of prime ice analogues of Pluto and Charon

Here we present the first Vacuum UltraViolet (VUV) photoabsorption spectra of ice analogues of Pluto and Charon ice mixtures. For Pluto the ice analogue is an icy mixture containing nitrogen (N2), carbon monoxide (CO), methane (CH4) and water (H2O) prepared with a 100:1:1:3 ratio, respectively. Photoabsorption of icy mixtures with and without H2O were recorded and no significant changes in the spectra due to presence of H2O were observed. For Charon a VUV photoabsorption spectra of an ice analogue containing ammonia (NH3) and H2O prepared with a 1:1 ratio was recorded, a spectrum of ammonium hydroxide (NH4OH) was also recorded. These spectra may help to interpret the P-Alice data from New Horizons

Evidence for spin-flip scattering and local moments in dilute fluorinated graphene

The issue of whether local magnetic moments can be formed by introducing adatoms into graphene is of intense research interest because it opens the window to fundamental studies of magnetism in graphene, as well as of its potential spintronics applications. To investigate this question we measure, by exploiting the well-established weak localization physics, the phase coherence length L_phi in dilute fluorinated graphene. L_phi reveals an unusual saturation below ~ 10 K, which cannot be explained by non-magnetic origins. The corresponding phase breaking rate increases with decreasing carrier density and increases with increasing fluorine density. These results provide strong evidence for spin-flip scattering and points to the existence of adatom-induced local magnetic moment in fluorinated graphene. Our results will stimulate further investigations of magnetism and spintronics applications in adatom-engineered graphene.Comment: 9 pages, 4 figures, and supplementary materials; Phys. Rev. Lett. in pres

Polynomials, Riemann surfaces, and reconstructing missing-energy events

We consider the problem of reconstructing energies, momenta, and masses in collider events with missing energy, along with the complications introduced by combinatorial ambiguities and measurement errors. Typically, one reconstructs more than one value and we show how the wrong values may be correlated with the right ones. The problem has a natural formulation in terms of the theory of Riemann surfaces. We discuss examples including top quark decays in the Standard Model (relevant for top quark mass measurements and tests of spin correlation), cascade decays in models of new physics containing dark matter candidates, decays of third-generation leptoquarks in composite models of electroweak symmetry breaking, and Higgs boson decay into two tau leptons.Comment: 28 pages, 6 figures; version accepted for publication, with discussion of Higgs to tau tau deca

Nucleation of quark matter in neutron stars cores

We consider the general conditions of quark droplets formation in high density neutron matter. The growth of the quark bubble (assumed to contain a sufficiently large number of particles) can be described by means of a Fokker-Planck equation. The dynamics of the nucleation essentially depends on the physical properties of the medium it takes place. The conditions for quark bubble formation are analyzed within the frameworks of both dissipative and non-dissipative (with zero bulk and shear viscosity coefficients) approaches. The conversion time of the neutron star to a quark star is obtained as a function of the equation of state of the neutron matter and of the microscopic parameters of the quark nuclei. As an application of the obtained formalism we analyze the first order phase transition from neutron matter to quark matter in rapidly rotating neutron stars cores, triggered by the gravitational energy released during the spinning down of the neutron star. The endothermic conversion process, via gravitational energy absorption, could take place, in a very short time interval, of the order of few tens seconds, in a class of dense compact objects, with very high magnetic fields, called magnetars.Comment: 31 pages, 2 figures, to appear in Ap

Generalized Darboux transformations for the KP equation with self-consistent sources

The KP equation with self-consistent sources (KPESCS) is treated in the framework of the constrained KP equation. This offers a natural way to obtain the Lax representation for the KPESCS. Based on the conjugate Lax pairs, we construct the generalized binary Darboux transformation with arbitrary functions in time $t$ for the KPESCS which, in contrast with the binary Darboux transformation of the KP equation, provides a non-auto-B\"{a}cklund transformation between two KPESCSs with different degrees. The formula for N-times repeated generalized binary Darboux transformation is proposed and enables us to find the N-soliton solution and lump solution as well as some other solutions of the KPESCS.Comment: 20 pages, no figure