The future of microstructure technology — The industry view

Downscaling of minimum device and circuit geometries has been the primary engine driving exponential improvements in integrated circuit density, performance and cost for 20 years or more. These improvements have permitted concomitant progress in electronic systems, and and are largely responsible for the growth of the market. Semiconductor device and circuit modeling predicts practical limits on these geometries, and analysis of current trends indicates that these limits will be reached for circuits comprising large portions of the IC market by the mid-90's.The limitations on downscaling are both device- and interconnection-related and encompass noise and reliability issues. The practical limits are in the range 0.3 – 0.5 micrometers, but limits of a somewhat more fundamental nature exist around 0.1 – 0.3 micrometers. Since the practical limits are expected to be reached in the early- to mid-'90's, keeping functional density on its current exponential trend for more than a few years after that will require revolutionary approaches to devices, interconnections, noise immunity, and fault-tolerace.The discontinuity which maturation of the evolutionary transistor-based technology will create will present a rare opportunity to “go back to the well” of science to create a new technology of potentially large and immediate impact. In our view, which we believe to be shared by the industry, this must be a technology which leverages the accumulated experience and investment in semiconductor manufacturing in order to maintain the downward cost trend. Much of the required basic research in semiconductor microstructures in the regimes of quantum size effects and tunneling is yet to be done. Filling in this research gap should be a major priority for the immediate future, and the ability to do this will depend on continued progress in microstructure fabrication.     

The 8π spectrometer

The 8π spectrometer installed at the TRIUMF-ISAC radioactive beam facility provides a powerful and versatile detection system for radioactive decay, allowing measurements of γ rays and conversion electrons with high resolution, tagging on β particles, and fast-timing measurements. The facility supports a wide program of research in the fields of nuclear structure, nuclear astrophysics and fundamental symmetries with low-energy radioactive beams.     

The Singular Kane Oscillator

The energy spectrum of carriers in narrow band gap semiconductor nanocrystals are studied theoretically taking into account the nonparabolicity of charge carriers dispersion laws. The confinement potential of nanocrystals is approximated to be λγ^2 ＋ λ1γ^-2, and the dispersion laws are considered within the framework of the three-band Kane model.     

The Terabyte Analysis Machine Project The Distance Machine：Performance Report

The Terabyte Analysis Machine Project is Developing hardware and software to analyze Terabyte scale datasets.The Distance Machine framework provides facilities to flexibly interface application specific indexing and partitioning algorthms to large scientific databases.     

The light σ-meson

In the framework of the dispersion relation N/D-approach, we restore the low-energy (IJ ^PC = 00^{+ +})-wave amplitude sewing it with the previously obtained K-matrix solution for the region 450-1900 MeV. The restored N/D-amplitude has a pole on the second sheet of the complex-s plane near the threshold, that is the light -meson. Received: 21 February 2000 / Accepted: 20 June 2000     

The two-dimensional one-component plasma at Γ=2: The semiperiodic strip

The one-component two-dimensional plasma is studied in a strip of finite width, replicated periodically parallel to the long axis of the strip. Exact results for the one- and two-particle distribution functions are found at coupling =q ²/kT =2. The system is inhomogeneous: the one- and two-particle distribution functions show long-range order.     

The Schrödinger-HJW Theorem

A concise presentation of Schrödinger's ancilla theorem (Proc. Camb. Phil. Soc. 32, 446 (1936)) and its several recent rediscoveries.     

The fluctuation–dissipation theorem

A system in equilibrium will in general exhibit microscopic fluctuations about the equilibrium state. The fluctuation–dissipation theorem relates the spectrum of these fluctuations to a solution of the macroscopic equation describing the approach to equilibrium from a non-equilibrium state. The aim here is to show exactly what the theorem is and how it is to be used. An account of the quantum version of the theorem is given in three parts, depending on the solution of the macroscopic equation used to express the fluctuations: the relaxation function, the response function or the Green function for continuous systems. Each part is illustrated with an example: charge fluctuations in an RLC circuit for the first two and electric field fluctuations in vacuum for the last.     

The Born–Infeld sphaleron

We study the SU(2) electroweak model in which the standard Yang–Mills coupling is supplemented by a Born–Infeld term. The deformation of the sphaleron and bisphaleron solutions due to the Born–Infeld term is investigated and new branches of solutions are exhibited. Especially, we find a new branch of solutions connecting the Born–Infeld sphaleron to the first solution of the Kerner–Gal'tsov series.     

The Tsallis–Laplace transform

We introduce here the q$q$-Laplace transform as a new weapon in Tsallis’ arsenal, discussing its main properties and analyzing some examples. The q$q$-Gaussian instance receives special consideration. Also, we derive the q$q$-partition function from the q$q$-Laplace transform.     

The P̅ANDA apparatus

The P?ANDA experiment will make use of cooled antiproton beams of unprecedented quality that will be available at the Facility for Antiproton and Ion Research (FAIR) in Darmstadt. The envisaged physics program includes: meson spectroscopy, baryon antibaryon production, baryon spectroscopy, hypernuclar physics, hadron properties in the nuclear medium and electromagnetic processes. This rich physics program asks for a general purpose apparatus. The design of the experiment is an advanced stage and the R&D phase is approaching its final phase, as resulted by most of the Technical Design Reports (TDRs) being already completed or under writing. In addition the production phase has already started for the electromagnetic calorimeter.     

The Green-Schwarz superstring σ-model

We study the Green-Schwarz superstring coupled to a ten-dimensional supergravity background. We exhibit the background and quantum invariances of the action expanded in terms of normal coordinates. In the presence of nontrivial fermionic background we go to components and identity the vertex operators for emitting the physical supergravity fields. A comparison with the Neveu-Schwarz-Ramond formalism is then obtained by going to light-cone gauge.     

The “split” iota

Within the context of a five channel mixing model the possibility is considered that the E(1420) originally seen in PP̄ annihilation at rest and originally believed to be a J^PC=1⁺⁺ state is actually a pseudoscalar state distinct from the ι(1460) seen in radiative ψ decay. The quark and glue content that this hypothesis implies and the consequences for branching ratios of the known pseudoscalars are discussed. The five channel mixing model includes the ground state pseudoscalars, their first radial excitations, and a glueball. Mixing terms include an SU(3) symmetric glueball-quark state coupling as well as the important two body intermediate state unitarity corrections. While a number of mathematically consistent solutions to the model are found, none are physically acceptable. It is concluded that the more likely scenario is that the E(1420) and the ι(1460) are the same state, and the fifth partner to the scheme lies in a higher mass range, above 1.7 GeV.     

The First-Quantized Theory of Photons

In near-field optics and optical tunnelling theory, photon wave mechanics, i.e. the first-quantized theory of photons, allows us to address the spatial field localization problem in a flexible manner which links smoothly to classical electromagnetics. We develop photon wave mechanics in a rigorous and unified way, based on which field quantization is obtained in a new way.     

The quasi–abelian limit

A new, non perturbative, eikonal method called the “quasi abelian limit” (QAL) is suggested for high energy quark (nucleon) scattering involving the exchange of all possible, non interacting, non abelian gluons (mesons). With this method, those functional integrals defining, e.g., the exchange of color cooordinates in quark–quark scattering, are replaced by a finite number of quadratures over a subset of their coordinates. Mathematically, this procedure is not rigourous, because an unjustified interchange of limits has been performed; physically, it corresponds to the observation that the non perturbative sum over all color–moment fluctuations can vanish at arbitrarily high energies. The QAL generates a result in agreement with a corrected, “contiguity” calculation, when the latter is summed over all perturbative orders. Received: 30 August 1999 /Published online: 17 March 2000     

The four-loop dilaton β-function

We employ the identity derived by Curci and Paffuti relating the metric and dilaton β-functions for the bosonic σ-model to deduce the O(α′³) (four-loop) dilaton β-function from the O(α′³) (three-loop) metric β-function. We also give details of an explicit four-loop calculation in partial confirmation of our result.