Direct detection of a microlens in the Milky Way

  • Alcock C.
  • Allsman R.
  • Alves D.
  • Axelrod T.
  • Becker A.
  • Bennett D.
  • Cook K.
  • Drake A.
  • Freeman K.
  • Geha M.
  • Griest K.
  • Keller S.
  • Lehner M.
  • Marshall S.
  • Minniti D.
  • Nelson C.
  • Peterson B.
  • Popowski P.
  • Pratt M.
  • Quinn P.
  • Stubbs C.
  • Sutherland W.
  • Tomaney A.
  • Vandehel T.

The nature of dark matter remains mysterious, with luminous material accounting for at most similar to 25 per cent of the baryons in the Universe(1,2). We accordingly undertook a survey looking for the microlensing of stars in the Large Magellanic Cloud (LMC) to determine the fraction of Galactic dark matter ...

Tunable near-infrared femtosecond soliton generation in photonic crystal fibres

  • Coen S.
  • Dudley J.
  • Lacourt P.
  • Ralph S.
  • Rhodes W.
  • Washburn B.
  • Windeler R.

Femtosecond Raman soliton generation, tunable from 850-1050 nm. has been demonstrated by pumping untapered photonic crystal fibre with 110fs pulses from a modelocked Ti:sapphire laser. Experimental results are in excellent agreement with the results of numerical simulations using an extended nonlinear Schrodinger equation.

Zero-bias anomaly in disordered wires

  • Andreev A.
  • Glazman L.
  • Mishchenko E.

We calculate the low-energy tunneling density of states v(epsilon, T) of an N-channel disordered wire, taking into account the electron-electron interaction nonperturbatively. The finite scattering rate 1/tau results in a crossover from the Luttinger liquid behavior at higher energies, v proportional to epsilon (alpha), to the exponential dependence v (epsilon, ...

Stability of HF-etched Si(100) surfaces in oxygen ambient

  • Chabal Y.
  • Chaban E.
  • Christman S.
  • Garfunkel E.
  • Zhang X.

In situ multiple internal reflection infrared absorption spectroscopy of H-passivated silicon surfaces in controlled oxygen environments reveals that direct oxygen incorporation into the surface Si-Si bonds occurs without surface hydrogen removal, in the temperature range of 550-590 K for 1-20 mTorr O-2 pressures. The kinetics of the O-2 insertion process ...

Fast organic electronic circuits based on ambipolar pentacene field-effect transistors (Retracted Article. See vol 82, pg 1313, 2003)

  • Kloc C.
  • Schon J.

Inverter circuits and ring oscillators have been prepared based on the organic semiconductor pentacene. High-purity pentacene single crystals and thin films exhibit ambipolar transport properties, i.e., n- and p-channel transistor activity. This feature is very attractive for complementary logic electronic circuits, since only one organic material has to be used. ...

Grain boundary transport and vapor sensing in alpha-sexithiophene

  • Crone B.
  • Dodabalapur A.
  • Kloc C.
  • Schon J.

The charge transport through an alpha -sexithiophene bi-crystal exposed to various gaseous agents is investigated in the temperature range from 4 to 300 K. This method allows a comparison between intragrain and grain boundary effects. The importance of grain boundaries for gas sensing applications is demonstrated. Charged trap states are ...

Analysis of heat flow in optical fiber devices that use microfabricated thin film heaters

  • Eggleton B.
  • Rogers J.
  • Salamon T.

This paper describes finite element analysis of heat flow in a new class of tunable optical fiber devices that uses thin film resistive heaters microfabricated on the surface of the fiber. The high rate of heat loss from these cylindrical microstructures and the relatively low thermal diffusivity of the glass ...

Tunneling from a correlated two-dimensional electron system transverse to a magnetic field

  • Dykman M.
  • Platzman P.
  • Sharpee T.

We show that in a magnetic field parallel to a two-dimensional (2D) electron layer, strong electron correlations can change the rate of tunneling from the layer to the 3D continuum exponentially. It leads to a specific density dependence of the escape rate. The mechanism is a dynamical Mossbauer-type recoil. in ...

Full counting statistics of a charge pump in the Coulomb blockade regime

  • Andreev A.
  • Mishchenko E.

We study full charge counting statistics (FCCS) of a charge pump based on a nearly open single electron transistor. The problem is mapped onto an exactly soluble problem of a nonequilibrium g=1/2 Luttinger liquid with an impurity. We obtain an analytic expression for the generating function of the transmitted charge ...

Water-saturated Si(100)-(2x1): Kinetic Monte Carlo simulations of thermal oxygen incorporation

  • Chabal Y.
  • Esteve A.
  • Queeney K.
  • Raghavachari K.
  • Rouhani M.
  • Weldon M.

An atomic scale model of thermal oxidation of Si(100) has been developed based on a kinetic Monte Carlo approach. This method makes it possible to analyze the effects of elementary mechanistic steps of oxidation on macroscopic surfaces. The initial thermal decomposition of chemisorbed hydroxyl groups resulting from water adsorption on ...

Microstructured optical fiber devices

  • Eggleton B.
  • Hale A.
  • Kerbage C.
  • Westbrook P.
  • Windeler R.

We present several applications of microstructured optical fibers and study their modal characteristics by using Bragg gratings inscribed into photosensitive core regions designed into the air-silica microstructure. The unique characteristics revealed in these studies enable a number of functionalities including tunability and enhanced nonlinearity that provide a platform for fiber ...

Atomic scale measurements of the interfacial electronic structure and chemistry of zirconium silicate gate dielectrics

  • Muller D.
  • Wilk G.

We have examined the interfaces in Zr-silicate gate dielectrics grown on Si substrates using electron energy loss spectroscopy. The Zr-silicate interface is found to be stable with the Si substrate and the polycrystalline silicon (poly-Si) electrode under annealing to 1050 degreesC. At this interface, a 0.35 nm wide Zr-free interface ...

High-quality MgB2 films on boron crystals with onset T-c of 41.7 K

  • Chen C.
  • Cheong S.
  • Cieplak M.
  • Guha S.
  • Horibe Y.
  • Hur N.
  • Sharma P.
  • Werder D.

The simple binary compound, MgB2, has created enormous excitement, due to its remarkably high T-c (39 K), its exotic electronic and phononic structure, as well as its potential technological application. However, contrary to the initial expectation, worldwide efforts to enhance the T-c of this material by means of chemical doping ...

On the stability of organic field-effect transistor materials

  • Schon J.

Stability and degradation of transistor performance of devices based on pentacene and alpha -sexithiophene are investigated. In order to distinguish between effects at grain boundaries and material issues, macroscopic bicrystals were used, where transistors were prepared on a single grain as well as across a single grain boundary. The main ...

The formation of ordered, ultrathin SiO2/Si(100) interfaces grown on (1 x 1) Si(100)

  • Atluri V.
  • Culbertson R.
  • Grams M.
  • Herbots N.
  • Hurst Q.
  • Shaw J.
  • Smith D.
  • Zimmerman P.

Ordering is observed at SiO2/Si(100) interfaces when 2-40 nm thick SiO2 films are grown on passivated, ordered (1 x 1) Si(100) surfaces produced by a novel wet chemical cleaning, A mechanism is proposed for the occurrence of this ordering. The thin oxides are grown by a variety of conventional oxidation ...

Creep deformation and stress-induced structural disorder near T-g in a Zr55Al10Ni5Cu30 glassy alloy

  • Chen H.
  • Inoue A.
  • Kato H.

Creep deformation under a constant applied load in a Zr55Al10Ni5Cu30 glassy alloy at the glass transition region is investigated. At an initial stress, sigma (0), less than a critical stress, sigma (c)=80 MPa, the glass shows a Newtonian flow. When sigma (0)greater than or equal to sigma (c), the flow ...

End-to-end queuing delay assessment in multi-service IP networks

  • Buchli M.
  • De Vleeschauwer D.
  • Kooij R.
  • Van Moffaert A.

Packet-based networks are more and more used to transport interactive streaming services like telephony and videophony. To guarantee a good quality for these services, the queuing delay and delay jitter introduced in the transport of voice or video flows over the packet-based network should be kept under control. Because data ...

Nonlinear spectral properties of stimulated brillouin scattering in plasma

  • Kozlov M.
  • Kuzora I.
  • Mckinstrie C.
  • Ovchinnikov K.
  • Silin V.
  • Uryupin S.
  • Vagin K.

New phenomena in which the stimulated Brillouin scattering (SBS) changes the number and magnitude of frequency shifts in a plasma upon a nonlinear increase in the pumping field intensity are discovered. It is found that the SBS becomes forbidden and then allowed again (upon a subsequent increase in the pumping ...

SIP: A routing protocol

  • Chiang T.
  • Gurbani V.
  • Kumar S.

Routing in the Internet has traditionally implied shunting packets based on layer 2 (network layer of the IP reference model) addresses. While that may have been adequate in the past, the new protocols of the Internet are moving routing to the highest layer-the application layer These protocols include established ones ...