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18 Feb 2008

Volume 92, Issue 7, Articles (07xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 92, 073101 (2008); http://dx.doi.org/10.1063/1.2840574 (3 pages)

N. W. Gong, M. Y. Lu, C. Y. Wang, Y. Chen, and L. J. Chen
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Low loss porous terahertz fibers containing multiple subwavelength holes

Alireza Hassani, Alexandre Dupuis, and Maksim Skorobogatiy

Appl. Phys. Lett. 92, 071101 (2008); http://dx.doi.org/10.1063/1.2840164 (3 pages) | Cited 23 times

Online Publication Date: 19 February 2008

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We propose a porous polymer terahertz fiber with a core composed of a hexagonal array of subwavelength air holes. Numerical simulations show that the larger part of guided power propagates inside the air holes within the fiber core, resulting in suppression of the bulk absorption losses of the core material by a factor of ∼ 10–20. Confinement of terahertz power in the subwavelength holes greatly reduces effective refractive index of the guided mode but not as much as to considerably increase modal radiation losses due to bending. As a result, tight bends of several centimeter bending radii can be tolerated.
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82.35.-x Polymers: properties; reactions; polymerization
81.05.Rm Porous materials; granular materials
61.82.Pv Polymers, organic compounds

Study of residual background carriers in midinfrared InAs/GaSb superlattices for uncooled detector operation

H. J. Haugan, S. Elhamri, F. Szmulowicz, B. Ullrich, G. J. Brown, and W. C. Mitchel

Appl. Phys. Lett. 92, 071102 (2008); http://dx.doi.org/10.1063/1.2884264 (3 pages) | Cited 9 times

Online Publication Date: 19 February 2008

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The midinfrared 7 ML InAs/8 ML GaSb superlattices (SLs) were grown by molecular beam epitaxy at growth temperatures between 370 and 430 °C in order to study the intrinsic characteristic of background carriers. Grown SLs were all residual p type with carrier densities in the low 1011 cm−2, and a minimum density of 1.8×1011 cm−2 was obtained from the SL grown at 400 °C. With increasing growth temperature, the in-plane carrier mobility decreased from 8740 to 1400 cm2/V s due to increased interfacial roughness, while the photoluminescence intensity increased sixfold due to a decrease in the nonradiative defect densities.
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68.65.Cd Superlattices
72.20.Ee Mobility edges; hopping transport
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.35.Ct Interface structure and roughness
85.60.Gz Photodetectors (including infrared and CCD detectors)
73.63.-b Electronic transport in nanoscale materials and structures

Giant stability enhancement of rare-earth implanted SiO2 light emitting devices by an additional SiON protection layer

J. M. Sun, L. Rebohle, S. Prucnal, M. Helm, and W. Skorupa

Appl. Phys. Lett. 92, 071103 (2008); http://dx.doi.org/10.1063/1.2870203 (3 pages) | Cited 8 times

Online Publication Date: 20 February 2008

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The electrical stability of rare-earth implanted SiO2 light emitting devices was improved by using a SiON dielectric buffer layer in an indium tin oxide/SiON/SiO2:Tb/Si device structure. At the expense of a small increase of the electroluminescence threshold voltage, a large increase of the breakdown electric field from 7.5 to 10.5 MV/cm was obtained in the SiO2:Tb layer, and the maximum injection current density was increased by three orders of magnitude from 4 mA/cm2 to 4 A/cm2. The operation time of the electroluminescence devices was increased by more than three orders of magnitude at an injection current density of ∼ 4 mA/cm2. Our experimental results are consistent with a theoretical model proposed for designing a stable and efficient thin-film light emitting device containing double-stacked dielectric layers.
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85.60.Jb Light-emitting devices
78.60.Fi Electroluminescence

Generation of ultrashort optical pulses using multiple coherent anti-Stokes Raman scattering in a crystal at room temperature

Eiichi Matsubara, Taro Sekikawa, and Mikio Yamashita

Appl. Phys. Lett. 92, 071104 (2008); http://dx.doi.org/10.1063/1.2883928 (3 pages) | Cited 18 times

Online Publication Date: 20 February 2008

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We demonstrate Fourier synthesis of multiple coherent anti-Stokes Raman scattering signals in a LiNbO3 crystal at room temperature. The signals up to the 20th order (470–800 nm) were generated by two crossing femtosecond Ti:sapphire laser pulses. Angle dispersion of the signals was compensated into one white-continuum beam by modifying a conventional 4f configuration. Spectral phase of the signal was measured by spectral phase interferometry for direct electric-field reconstruction. Isolated pulses with 25 fs duration at 1 kHz were generated only by appropriately aligning the angle-dispersion compensator. This result opens the possibility of the generation of subfemtosecond pulses in the visible region.
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42.65.Re Ultrafast processes; optical pulse generation and pulse compression
42.65.Dr Stimulated Raman scattering; CARS
42.65.Es Stimulated Brillouin and Rayleigh scattering

Red single-photon emission from an InP/GaInP quantum dot embedded in a planar monolithic microcavity

Robert Roßbach, Matthias Reischle, Gareth J. Beirne, Michael Jetter, and Peter Michler

Appl. Phys. Lett. 92, 071105 (2008); http://dx.doi.org/10.1063/1.2883946 (3 pages) | Cited 5 times

Online Publication Date: 20 February 2008

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Using micro-photoluminescence, we demonstrate single-photon emission in the visible (red) spectral range using self-assembled InP quantum dots embedded in a planar microcavity realized by monolithically grown high reflectivity AlGaAs distributed Bragg reflectors. A full width at half maximum of 130 μeV at 5 K was observed from a single quantum dot coupled to the fundamental cavity resonance. Photon correlation measurements performed under continuous wave excitation show a clear antibunching behavior [g(2)(0) = 0.13] as expected for a single-photon emitter. Saturation count rates up to 1.5 MHz (8.1 MHz into the first lens, with an extraction efficiency of 4.1%) were observed.
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78.67.Hc Quantum dots
78.55.Cr III-V semiconductors

Linewidth enhancement factor of terahertz quantum cascade lasers

Richard P. Green, Ji-Hua Xu, Lukas Mahler, Alessandro Tredicucci, Fabio Beltram, Guido Giuliani, Harvey E. Beere, and David A. Ritchie

Appl. Phys. Lett. 92, 071106 (2008); http://dx.doi.org/10.1063/1.2883950 (3 pages) | Cited 12 times

Online Publication Date: 20 February 2008

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The linewidth enhancement factor (LEF) of terahertz quantum cascade lasers is measured using an optical feedback self-mixing technique. As expected, a much lower LEF is found than is common for interband lasers, but instead of the predicted value of zero, the LEF depends on the laser conditions and can be as high as 0.5. The measured value tends to increase with increasing current. Cross absorption within the laser active region is suggested as a possible cause for the nonzero LEF observed.
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42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Microscopic calculation and measurement of the laser gain in a (GaIn)Sb quantum well structure

C. Bückers, A. Thränhardt, S. W. Koch, M. Rattunde, N. Schulz, J. Wagner, J. Hader, and J. V. Moloney

Appl. Phys. Lett. 92, 071107 (2008); http://dx.doi.org/10.1063/1.2883952 (3 pages) | Cited 7 times

Online Publication Date: 20 February 2008

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A detailed microscopic calculation and experimental measurements of the optical gain from a (GaIn)Sb structure are presented. For a given excitation density, the gain in the (GaIn)Sb material system considerably exceeds that of a comparable equivalent (GaIn)As/GaAs structure. The physical reasons for this high gain are analyzed and attributed mostly to band structure effects.
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42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems
42.70.Hj Laser materials

A microfluidic refractive index sensor based on an integrated three-dimensional photonic crystal

Jing Wu, Daniel Day, and Min Gu

Appl. Phys. Lett. 92, 071108 (2008); http://dx.doi.org/10.1063/1.2840700 (3 pages) | Cited 15 times

Online Publication Date: 20 February 2008

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We present the concept of using three-dimensional photonic crystals for refractive index sensing in a microfluidic channel. The sensors are based on a three-dimensional void channel photonic crystal fabricated by femtosecond laser writing in a polymer substrate. It is demonstrated that a change in the refractive index of the fluid in the microchannel results in a shift in the band gap or band gap defect position of the photonic crystal. According to Fourier transform infared spectroscopy of the photonic crystal sensor, a change of 6×10−3 in the refractive index of the fluid can be detected.
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42.82.-m Integrated optics
47.85.Np Fluidics
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
85.85.+j Micro- and nano-electromechanical systems (MEMS/NEMS) and devices

A low-loss, robust setup for double optical gating of high harmonic generation

Steve Gilbertson, Hiroki Mashiko, Chengquan Li, Sabih D. Khan, Mahendra M. Shakya, Eric Moon, and Zenghu Chang

Appl. Phys. Lett. 92, 071109 (2008); http://dx.doi.org/10.1063/1.2883979 (3 pages) | Cited 17 times

Online Publication Date: 20 February 2008

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Previously, a second harmonic field was added to a polarization gating field by a Mach–Zehnder interferometer to gate the high harmonic generation process in argon gas. To reduce the losses of the interferometer, we developed a collinear setup consisting of only two quartz plates and a barium borate crystal. The high intensity at the focus allowed the double optical gating to be performed on neon gas. As a result, a supercontinuous spectrum was produced capable of supporting 130 as. There is no delay jitter between the second harmonic field and the polarization gating field associated in this setup, which is necessary for generating stable single isolated attosecond pulses.
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42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
07.60.Ly Interferometers
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
51.70.+f Optical and dielectric properties

Broad-stripe, single-mode, mid-IR interband cascade laser with photonic-crystal distributed-feedback grating

C. S. Kim, M. Kim, W. W. Bewley, J. R. Lindle, C. L. Canedy, J. A. Nolde, D. C. Larrabee, I. Vurgaftman, and J. R. Meyer

Appl. Phys. Lett. 92, 071110 (2008); http://dx.doi.org/10.1063/1.2884189 (3 pages) | Cited 7 times

Online Publication Date: 20 February 2008

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We have demonstrated an electrically pumped photonic-crystal distributed-feedback laser with an interband cascade active region emitting at 3.3 μm. At 78 K, the stripe of width 400 μm emits up to 67 mW of cw power into a single spectral mode with side-mode suppression ratio ≈ 27 dB. The full width at half maximum of the far-field divergence angle is ≈ 0.5°, which combined with the near-field profile yields an effective M2 of 1.7–2.0.
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42.55.Tv Photonic crystal lasers and coherent effects
42.70.Qs Photonic bandgap materials
42.79.Dj Gratings
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation

Highly collimated laser emission from a peanut-shaped microcavity

Lei Shang, Liying Liu, and Lei Xu

Appl. Phys. Lett. 92, 071111 (2008); http://dx.doi.org/10.1063/1.2839383 (3 pages) | Cited 6 times

Online Publication Date: 21 February 2008

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Highly collimated laser emission from a largely deformed microcavity laser (peanut-shaped microcavity laser) was observed. Emission divergence of 2° was achieved. The microcavity laser was found to be operated on a hybrid lasing mode that formed with a combination of whispering gallery orbit and multiple-bouncing orbit.
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42.55.Sa Microcavity and microdisk lasers
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Microfabricated water immersion zone plate optical tweezer

Ethan Schonbrun, Charles Rinzler, and Kenneth B. Crozier

Appl. Phys. Lett. 92, 071112 (2008); http://dx.doi.org/10.1063/1.2837538 (3 pages) | Cited 14 times

Online Publication Date: 21 February 2008

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We demonstrate the trapping of beads in water with a microfabricated Fresnel zone plate. Beads are loaded onto the microfabricated optical traps using conventional optical tweezers and fluorescence microscopy is used to track bead position. Analysis of the bead position as a function of time is used to determine trapping stiffness. We present experiments showing the three-dimensional trapping of 2 μm diameter beads with trapping stiffnesses that are comparable to conventional optical tweezers when the zone plate efficiency is taken into account.
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42.50.Wk Mechanical effects of light on material media, microstructures and particles

Photovoltaic effects and its oxygen content dependence in BaTiO3−δ/Si heterojunctions

Jie Xing, Kui-Juan Jin, Huibin Lu, Meng He, Guozhen Liu, Jie Qiu, and Guozhen Yang

Appl. Phys. Lett. 92, 071113 (2008); http://dx.doi.org/10.1063/1.2884320 (3 pages) | Cited 12 times

Online Publication Date: 21 February 2008

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Three oxide heterojunctions made of BaTiO3−δ/Si have been fabricated under various oxygen pressures by laser molecular beam epitaxy. They all exhibited nonlinear and rectifying I-V characteristics but with a large difference in the rectification behaviors. Their photoelectric properties and dependences on oxygen contents in BaTiO3−δ films have been experimentally studied. We found that the photovoltaic effects depended strongly on the oxygen contents of the BaTiO3−δ films. The possible mechanism was proposed based on the band structure of the p-n heterojunctions.
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73.50.Pz Photoconduction and photovoltaic effects
68.55.A- Nucleation and growth
73.20.At Surface states, band structure, electron density of states
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
73.61.-r Electrical properties of specific thin films

Polarization beam splitting through an anisotropic metamaterial slab realized by a layered metal-dielectric structure

Junming Zhao, Yan Chen, and Yijun Feng

Appl. Phys. Lett. 92, 071114 (2008); http://dx.doi.org/10.1063/1.2884322 (3 pages) | Cited 9 times

Online Publication Date: 21 February 2008

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We report a polarization beam splitter (PBS) utilizing the anomalous reflection and transmission of an anisotropic metamaterial slab. By properly design of the constitutive tensors of the slab, PBS is achieved with little dependence on incident angle and slab thickness. The realization of the proposed PBS in the optical range is achieved by layered metal-dielectric nanostructured system, which could be modeled as an effective anisotropic metamaterial with the desired constitutive tensors. The full-wave electromagnetic simulation has confirmed the optical polarization splitting with an extinction ratio of over 20 dB by a slab of an alternating silver and silicon carbide multilayer.
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42.79.Fm Reflectors, beam splitters, and deflectors
42.79.Wc Optical coatings
42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials

Control of spontaneous emission coupling factor β in fiber-coupled microsphere resonators

Hideaki Takashima, Hideki Fujiwara, Shigeki Takeuchi, Keiji Sasaki, and Masahide Takahashi

Appl. Phys. Lett. 92, 071115 (2008); http://dx.doi.org/10.1063/1.2884329 (3 pages) | Cited 9 times

Online Publication Date: 21 February 2008

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The spontaneous emission coupling factor β is studied for fiber-coupled microspheres with a thin gain layer of phosphorus codoped sol-gel erbium silica-aluminum glass. From the input-output characteristics of the lasing, β = 0.039 is estimated for a sample with a gain layer on the sphere surface. β is estimated to increase to 0.19 when an additional silica glass thin layer is overcoated to improve the overlap between the gain layer and the optical mode of the lasing inside the sphere.
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42.55.Wd Fiber lasers
42.81.Qb Fiber waveguides, couplers, and arrays

Electric-field tuning s-d exchange interaction in quantum dots

X. J. Li and Kai Chang

Appl. Phys. Lett. 92, 071116 (2008); http://dx.doi.org/10.1063/1.2884696 (3 pages) | Cited 4 times

Online Publication Date: 21 February 2008

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We investigate theoretically the electron-hole pair states in CdTe quantum dot (QD) containing a single Mn2+ ion by the magneto-optical spectrum tuned by the electric field. It is shown that the electric field does not only tune the spin splitting via the sp-d exchange interaction but also affect significantly the anticrossing behavior in the photoluminescence spectrum. This anticrossing is caused by the s-d exchange interaction and/or the hole mixing effect, which depends sensitively on the shape of the QD.
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71.70.Gm Exchange interactions
78.20.Ls Magneto-optical effects
78.55.Et II-VI semiconductors
78.67.Hc Quantum dots

Magneto-optical isolator with silicon waveguides fabricated by direct bonding

Yuya Shoji, Tetsuya Mizumoto, Hideki Yokoi, I-Wei Hsieh, and Richard M. Osgood, Jr.

Appl. Phys. Lett. 92, 071117 (2008); http://dx.doi.org/10.1063/1.2884855 (3 pages) | Cited 31 times

Online Publication Date: 21 February 2008

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A magneto-optical isolator is demonstrated for use with a Si waveguide. The isolator is based on a Mach–Zehnder interferometer employing a nonreciprocal phase shift and is fabricated by bonding a magneto-optic garnet CeY2Fe5O12 (Ce:YIG) directly onto the Si waveguide. The surface-activated bonding is based on oxygen-plasma exposure in a high-vacuum chamber. The nonreciprocal phase shift is observed by applying an external magnetic field. An isolation ratio of 21 dB is obtained at a wavelength of 1559 nm.
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42.82.Et Waveguides, couplers, and arrays
85.70.Sq Magnetooptical devices
07.60.Ly Interferometers
42.82.Cr Fabrication techniques; lithography, pattern transfer
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Diagnostics for low-energy electrons in a two-frequency capacitively coupled plasma in Ar

M. Ishimaru, T. Ohba, T. Ohmori, T. Yagisawa, T. Kitajima, and T. Makabe

Appl. Phys. Lett. 92, 071501 (2008); http://dx.doi.org/10.1063/1.2844890 (3 pages) | Cited 11 times

Online Publication Date: 19 February 2008

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An experimental procedure to investigate the spatiotemporal characteristics of electrons in the vicinity of mean energy in a radiofrequency plasma is proposed by using optical emission and absorption spectroscopy in Ar. The method employs optical kinetics of long-lived metastable atom Ar(1s5) and short-lived excited Ar(2p9). The electron density distribution ne(z,t) is demonstrated in a typical condition in a two-frequency capacitively coupled plasma, excited at 100 MHz and biased at 500 kHz in pure Ar. The density shows almost time independent characteristics in the bulk plasma and a strong time dependence in the sheath in front of the bias electrode.
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52.70.-m Plasma diagnostic techniques and instrumentation
52.25.-b Plasma properties
52.80.-s Electric discharges
52.40.Kh Plasma sheaths

Intense-laser generated relativistic electron transport in coaxial two-layer targets

C. T. Zhou, X. T. He, and M. Y. Yu

Appl. Phys. Lett. 92, 071502 (2008); http://dx.doi.org/10.1063/1.2884334 (3 pages) | Cited 12 times

Online Publication Date: 21 February 2008

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The transport and heating of laser produced relativistic electron beam propagating through coaxial two-layer solid-density plasma are studied using two-dimensional hybrid fluid-particle-in-cell simulation. When the energetic electrons enter the plastic and copper target, stronger heating is observed in the plastic plasma. The heating of the plasma electrons and the formation of tens of million Gauss interface magnetic fields results from a large difference of the velocities of the returning electrons at the two sides of the interface. Moreover, the electron beam can have a completely different emittance behavior when the target consists of different-material layers.
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52.50.Jm Plasma production and heating by laser beams (laser-foil, laser-cluster, etc.)
52.40.Mj Particle beam interactions in plasmas
41.75.Ht Relativistic electron and positron beams

Destruction of dimethyl methylphosphonate using a microwave plasma torch

Han S. Uhm, Soon C. Cho, Yong C. Hong, Yang G. Park, and Ju S. Park

Appl. Phys. Lett. 92, 071503 (2008); http://dx.doi.org/10.1063/1.2844859 (3 pages) | Cited 4 times

Online Publication Date: 21 February 2008

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A microwave plasma torch with a microwave power of 1.2 kW destroys dimethyl methylphosphonate (DMMP) with a destruction rate of 1.14 l/h, demonstrating a safe removal capability of stockpiled chemical weapons. The FTIR spectra of the discharge gas from DMMP destruction indicates near perfect elimination of DMMP when the proper amount of oxygen gas is added. This can be confirmed by the gas chromatography spectra, which show the disappearance of even intermediary compounds. The compactness and light weight of the microwave plasma torch provide an effective means of on-site removal of the chemical warfare agents found on a battlefield.
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52.75.Hn Plasma torches
89.20.Dd Military technology and weapons systems; arms control
78.30.-j Infrared and Raman spectra

Cross-talk in multiple dielectric barrier discharge actuators

H. Do, W. Kim, M. A. Cappelli, and M. G. Mungal

Appl. Phys. Lett. 92, 071504 (2008); http://dx.doi.org/10.1063/1.2885085 (3 pages) | Cited 4 times

Online Publication Date: 21 February 2008

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Phase locked particle image velocimetry (PIV) is used to study flow alteration by dielectric barrier discharge actuators mounted on a bluff body. Images from these PIV experiments confirm the importance of negative ions in the actuation process and demonstrate cross-talk interactions between adjacent actuators.
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47.85.ld Boundary layer control
47.80.Jk Flow visualization and imaging
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GaAs interfacial self-cleaning by atomic layer deposition

C. L. Hinkle, A. M. Sonnet, E. M. Vogel, S. McDonnell, G. J. Hughes, M. Milojevic, B. Lee, F. S. Aguirre-Tostado, K. J. Choi, H. C. Kim, J. Kim, and R. M. Wallace

Appl. Phys. Lett. 92, 071901 (2008); http://dx.doi.org/10.1063/1.2883956 (3 pages) | Cited 121 times

Online Publication Date: 19 February 2008

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The reduction and removal of surface oxides from GaAs substrates by atomic layer deposition (ALD) of Al2O3 and HfO2 are studied using in situ monochromatic x-ray photoelectron spectroscopy. Using the combination of in situ deposition and analysis techniques, the interfacial “self-cleaning” is shown to be oxidation state dependent as well as metal organic precursor dependent. Thermodynamics, charge balance, and oxygen coordination drive the removal of certain species of surface oxides while allowing others to remain. These factors suggest proper selection of surface treatments and ALD precursors can result in selective interfacial bonding arrangements.
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81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
82.30.-b Specific chemical reactions; reaction mechanisms
79.60.Bm Clean metal, semiconductor, and insulator surfaces
81.65.Mq Oxidation
65.40.G- Other thermodynamical quantities
81.65.Cf Surface cleaning, etching, patterning

An analytical model of effective electrical conductivity of carbon nanotube composites

Fei Deng and Quan-Shui Zheng

Appl. Phys. Lett. 92, 071902 (2008); http://dx.doi.org/10.1063/1.2857468 (3 pages) | Cited 16 times

Online Publication Date: 19 February 2008

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Experiments on electrical properties of carbon nanotube (CNT) composites have shown that addition of CNTs may greatly enhance the electrical conductivity of the matrix. It has been a key but unresolved issue for years how to develop an analytical model of effective electrical conductivity of CNT composites that takes account of not only the CNT concentration and percolation, but also CNT conductivity anisotropy, aspect ratio, and nonstraightness. Such a model is established in this letter. The model predictions agree well with the measured data available in literatures and are also extended to account the effect of the orientation distribution of CNTs.
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61.46.Fg Nanotubes
72.80.Rj Fullerenes and related materials
73.61.Wp Fullerenes and related materials

First-principles study of the effect of nitrogen vacancies on the decomposition pattern in cubic Ti1−xAlxN1−y

B. Alling, A. Karimi, L. Hultman, and I. A. Abrikosov

Appl. Phys. Lett. 92, 071903 (2008); http://dx.doi.org/10.1063/1.2838747 (3 pages) | Cited 9 times

Online Publication Date: 21 February 2008

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The effect of nitrogen substoichiometry on the isostructural phase stabilities of the cubic Ti1−xAlxN1−y system has been investigated using first-principles calculations. The preferred isostructural decomposition pattern in these metastable solid solutions was predicted from the total energy calculations on a dense concentration grid. Close to the stoichiometric Ti1−xAlxN1 limit, N vacancies increase the tendency for phase separation as N sticks to Al while the vacancies prefers Ti neighbors. For nitrogen depleated conditions, N sticks to Ti forming TiNδ (0<δ<1) while Al tends to form nitrogen-free fcc-Al or Al–Ti alloys.
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61.72.jd Vacancies
61.66.Bi Elemental solids
61.66.Dk Alloys
64.75.Nx Phase separation and segregation in solid solutions

Role of charge-transfer states of Cr3+ in creation and annihilation of light-induced polarons in LiNbO3:Cr3+, MgO crystals

S. Kobyakov, A. Suchocki, L. Arizmendi, and F. Jaque

Appl. Phys. Lett. 92, 071904 (2008); http://dx.doi.org/10.1063/1.2884265 (3 pages)

Online Publication Date: 21 February 2008

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It is shown that Cr impurity takes a crucial role in the process of creation of hole O− and electron NbNb4+ polarons by the UV light in LiNbO3:Cr crystal codoped with MgO above threshold concentration. Thermal stability of both types of polarons shows that they are created and they annihilate simultaneously with each other in such crystals.
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71.38.-k Polarons and electron-phonon interactions
71.55.Ht Other nonmetals
78.60.Kn Thermoluminescence
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