APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

10 Jul 2006

Volume 89, Issue 2, Articles (02xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 89, 023901 (2006); http://dx.doi.org/10.1063/1.2219984 (3 pages)

Nikhil Ganesh, Ian D. Block, and Brian T. Cunningham
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Laser impulse generation and interferometer detection of zero group velocity Lamb mode resonance

Dominique Clorennec, Claire Prada, Daniel Royer, and Todd W. Murray

Appl. Phys. Lett. 89, 024101 (2006); http://dx.doi.org/10.1063/1.2220010 (3 pages) | Cited 12 times

Online Publication Date: 10 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this letter, we describe experiments on the generation of the first order symmetric (S1) Lamb mode by a pulsed yttrium aluminum garnet laser. The vibration of the plate is detected at the same point by a heterodyne interferometer. The acoustic signal is dominated by the resonance at the point of the dispersion curve where the group velocity vanishes. The time decay of the signal leads to the local attenuation coefficient of the material. The spectrum exhibits a very sharp peak, the frequency of which is sensitive to the plate thickness. For a 0.49-mm-thick Duralumin plate, thickness variations as small as 0.1 μm have been detected. Moving the detection point away from the source allows us to record the standing wave pattern resulting from the interference between the S1 and S2b Lamb waves having opposite wave vectors at the zero group velocity point.
Show PACS
43.35.Zc
81.70.Cv Nondestructive testing: ultrasonic testing, photoacoustic testing
46.40.Ff Resonance, damping, and dynamic stability

Millimeter wave analysis of the dielectric properties of oil shales

John A. Scales and Michael Batzle

Appl. Phys. Lett. 89, 024102 (2006); http://dx.doi.org/10.1063/1.2219720 (3 pages) | Cited 4 times

Online Publication Date: 11 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Natural sedimentation processes give rise to fine layers in shales. If these layers alternate between organic-rich and organic-poor sediments, then the contrast in dielectric properties gives rise to an effective birefringence as the presence of hydrocarbons suppresses the dielectric constant of the host rock. We have measured these effects with a quasioptical millimeter wave setup that is rapid and noncontacting. We find that the strength of this birefringence and the overall dielectric permittivity provide two useful diagnostics of the organic content of oil shales.
Show PACS
91.60.Pn Magnetic and electrical properties
91.60.Mk Optical properties
77.22.Ch Permittivity (dielectric function)
78.20.Fm Birefringence

In situ pendeoepitaxy of GaN using heteroepitaxial AlGaN/GaN cracks

Y. T. Moon, C. Liu, J. Xie, X. Ni, Y. Fu, H. Morkoç, Lin Zhou, and David J. Smith

Appl. Phys. Lett. 89, 024103 (2006); http://dx.doi.org/10.1063/1.2219093 (3 pages) | Cited 1 time

Online Publication Date: 11 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Pendeoepitaxy on patterned templates has been proven to be efficient for reducing threading dislocation densities in GaN thin films. In this letter, we report on in situ crack-assisted pendeoepitaxy of GaN using spontaneously formed cracks in AlGaN/GaN heterostructures. Our approach involves the growth of an AlGaN/GaN template followed by in situ thermal etching and deposition of an amorphous silicon nitride mask in a low pressure metal organic chemical vapor deposition system. Microwirelike GaN seeds are then formed along the crack lines during the initial stage of GaN overgrowth, which act as nucleation stripes for epitaxial lateral overgrowth. Transmission electron microscopy revealed that the lateral overgrowth of the wirelike GaN seeds effectively bends threading dislocations toward 〈1math00〉 directions on the amorphous silicon nitride mask. The threading dislocation density by this method has been reduced from 2×109 cm−2 in control samples to 2×108 cm−2 in some parts and 5×107 cm−2 in other parts of the GaN layer as determined by plan-view transmission electron microscopy which is very encouraging.
Show PACS
81.05.Ea III-V semiconductors
68.55.A- Nucleation and growth
81.40.Np Fatigue, corrosion fatigue, embrittlement, cracking, fracture, and failure
62.20.M- Structural failure of materials
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)

Rheology of complex fluids by particle image velocimetry in microchannels

Guillaume Degré, Pierre Joseph, Patrick Tabeling, Sandra Lerouge, Michel Cloitre, and Armand Ajdari

Appl. Phys. Lett. 89, 024104 (2006); http://dx.doi.org/10.1063/1.2221501 (3 pages) | Cited 28 times

Online Publication Date: 12 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We image the flow of complex fluids in microchannels of controlled geometry using tracers. The spatial resolution allows us to access quantitatively the bulk nonlinear rheology and wall slip, as we show on model polymer solutions. In perspective this strategy should prove useful for the study of heterogeneous flows of more complex fluids.
Show PACS
47.57.Qk Rheological aspects
47.57.Ng Polymers and polymer solutions
47.80.Jk Flow visualization and imaging
47.60.-i Flow phenomena in quasi-one-dimensional systems
47.45.Gx Slip flows and accommodation
83.80.Rs Polymer solutions

Ionic to mixed ionic/electronic conduction transition of chemically lithiated Li0.33La0.56TiO3 at room temperature: Lithium-ion-motion dependent electron hopping

Kai-Yun Yang and Kuan-Zong Fung

Appl. Phys. Lett. 89, 024105 (2006); http://dx.doi.org/10.1063/1.2220480 (3 pages)

Online Publication Date: 13 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The interfacial instability of metallic lithium and cation-vacant lithium lanthanum titanate results in the presence of Ti3+ donors and an increased number of Li+ ions at the Li0.33La0.56TiO3 side. It is clarified that the intercalated Li+ ion and the Ti-site electron are favorable to form a coupled Li+/e− state to maintain the lowest electrostatic potential energy. Through the motion of these states, the interfacial instability is reflected in the electrical transition of Li0.33La0.56TiO3, in which the change of bulk electronic conduction from an insulator to a n-type semiconductor is determined by the lithium-ion-motion dependent electron hopping.
Show PACS
66.30.H- Self-diffusion and ionic conduction in nonmetals
72.60.+g Mixed conductivity and conductivity transitions
72.20.Ee Mobility edges; hopping transport

Feature-size reduction of photopolymerized structures by femtosecond optical curing of SU-8

Kock Khuen Seet, Saulius Juodkazis, Vygandas Jarutis, and Hiroaki Misawa

Appl. Phys. Lett. 89, 024106 (2006); http://dx.doi.org/10.1063/1.2221499 (3 pages) | Cited 32 times

Online Publication Date: 13 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The universal scaling of a width of photopolymerized line on the exposure dose was observed in polymerization by direct laser writing using tightly focused femtosecond pulses in SU-8 resist. This scaling can be explained as the photopolymerization by a blackbody-type emission. A spectrally broad thermal emission of electrons heated up to temperatures approximately Te ∼ 103 K coincides with an IR-absorption band of SU-8 centered at the 2.9 μm and had caused polymerization by a cumulative direct absorption. Three-dimensional photonic crystal templates with approximately twice reduced feature size were fabricated with stop band at the fiber communication wavelength of 1.3 μm.
Show PACS
42.70.Jk Polymers and organics
42.70.Qs Photonic bandgap materials
42.62.-b Laser applications
82.35.-x Polymers: properties; reactions; polymerization

Experimental implementation of a quantum algorithm in a multiqubit NMR system formed by an oriented 7/2 spin

Ranabir Das and Anil Kumar

Appl. Phys. Lett. 89, 024107 (2006); http://dx.doi.org/10.1063/1.2218323 (3 pages) | Cited 6 times

Online Publication Date: 14 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A growing appreciation among researchers is the use of quadrupolar nuclei with spin >1/2 as a suitable candidate for quantum information processing. Such systems have multiple qubits per nuclei and large quadrupolar couplings, resulting in well separated lines in the spectrum. Preparation of pseudopure states and implementation of logic gates have been demonstrated in these systems. Two-qubit quantum algorithms have also been implemented in spin-3/2 systems. In this letter we report implementation of three-qubit Deutsch-Jozsa algorithm [ Proc. R. Soc. London, Ser. A 693, 553 (1992) ] in a spin-7/2 system of math nucleus oriented in a liquid crystalline matrix.
Show PACS
03.67.Lx Quantum computation architectures and implementations
42.70.Df Liquid crystals
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close