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

16 Jul 2012

Volume 101, Issue 3, Articles (03xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 101, 033301 (2012); http://dx.doi.org/10.1063/1.4734240 (5 pages)

Ting-Gang Chen, Bo-Yu Huang, En-Chen Chen, Peichen Yu, and Hsin-Fei Meng
Enlarge Image | Read More
Page 1 of 5 Pages Next Page | Jump to Page
back to top
RSS Feeds

Nanofocusing enhancement in a tapered slit by using a dielectric micro isosceles triangle prism and tuning the entrance aperture

Dengfeng Kuang, Sheng Ouyang, and Zhongxun Du

Appl. Phys. Lett. 101, 031101 (2012); http://dx.doi.org/10.1063/1.4737206 (3 pages)

Online Publication Date: 16 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present a combined configuration consisting of a dielectric micro isosceles triangular prism and a metallic tapered slit for enhanced nanofocusing. The dielectric micro isosceles triangular prism collects the incident light first and then the tapered slit guides the beam to form naofocusing with higher intensity at the exit aperture of the tapered slit, which overcomes the limit of the extremely small entrance aperture diaphragm of the slit. With the help of the dielectric micro isosceles triangular prism, the intensity of the nanofocused electric field at the exit aperture of the tapered slit can be increased more than 4 folds.
Show PACS
42.79.-e Optical elements, devices, and systems
42.79.Bh Lenses, prisms and mirrors
42.15.-i Geometrical optics

Phase assembly and photo-induced current in CdTe-ZnO nanocomposite thin films

R. J. Beal, J. B. Kana Kana, and B. G. Potter, Jr.

Appl. Phys. Lett. 101, 031102 (2012); http://dx.doi.org/10.1063/1.4736862 (5 pages)

Online Publication Date: 16 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Sequential radio-frequency sputtering was used to produce CdTe-ZnO nanocomposite thin films with varied semiconductor-phase extended structures. Control of the spatial distribution of CdTe nanoparticles within the ZnO embedding phase was used to influence the semiconductor phase connectivity, contributing to both changes in quantum confinement induced spectral absorption and carrier transport characteristics of the resulting nanocomposite. An increased number density of CdTe particles deposited along the applied field direction produced an enhancement in the photo-induced current observed. These results highlight the opportunity to employ long-range phase assembly as a means to control optoelectronic properties of significant interest for photovoltaic applications.
Show PACS
81.16.-c Methods of micro- and nanofabrication and processing
61.46.Df Structure of nanocrystals and nanoparticles ("colloidal" quantum dots but not gate-isolated embedded quantum dots)
68.55.-a Thin film structure and morphology
72.40.+w Photoconduction and photovoltaic effects
79.60.Dp Adsorbed layers and thin films
81.15.Cd Deposition by sputtering

Terahertz wavefront measurement with a Hartmann sensor

H. Richter, M. Greiner-Bär, N. Deßmann, J. Pfund, M. Wienold, L. Schrottke, R. Hey, H. T. Grahn, and H.-W. Hübers

Appl. Phys. Lett. 101, 031103 (2012); http://dx.doi.org/10.1063/1.4737164 (3 pages) | Cited 1 time

Online Publication Date: 17 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The measurement of the wavefront of a terahertz (THz) beam is essential for the development of any optical instrument operating at THz frequencies. We have realized a Hartmann wavefront sensor for the THz frequency range. The sensor is based on an aperture plate consisting of a regular square pattern of holes and a microbolometer camera. The performance of the sensor is demonstrated by characterizing the wavefront of a THz beam emitted by a quantum-cascade laser. The wavefront determined by the sensor agrees well with that expected from a Gaussian-shaped beam. The spatial resolution is 1 mm, and a single-wavefront measurement takes less than 1 s.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
42.79.Pw Imaging detectors and sensors

Self-organized InAs/InGaAsP quantum dot tube lasers

Pablo Bianucci, Shouvik Mukherjee, M. Hadi Tavakoli Dastjerdi, Philip J. Poole, and Zetian Mi

Appl. Phys. Lett. 101, 031104 (2012); http://dx.doi.org/10.1063/1.4737425 (4 pages) | Cited 2 times

Online Publication Date: 17 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the achievement of a semiconductor tube laser that can operate in the optical communication wavelength range for applications in the emerging Si-photonics. Such nanoscale devices are fabricated from self-organized InAs/InGaAsP quantum dot nanomembranes through a strain-driven self-rolling mechanism using standard photolithography process. Under continuous wave optical pumping, the devices exhibit an ultralow lasing threshold of ∼1.26 μW at 82 K, with multiple emission wavelengths in the S band of optical communications. The spontaneous emission coupling factor and Purcell factor are estimated to be ∼0.30 and ∼4.8, respectively.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems
42.79.-e Optical elements, devices, and systems

Chiral meta-atoms rotated by light

Mingkai Liu, David A. Powell, and Ilya V. Shadrivov

Appl. Phys. Lett. 101, 031105 (2012); http://dx.doi.org/10.1063/1.4737441 (4 pages) | Cited 1 time

Online Publication Date: 17 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We study the opto-mechanical properties of coupled chiral meta-atoms based on a pair of twisted split-ring resonators. By using a simple analytical model in conjunction with the Maxwell stress tensor, we capture insight into the mechanism and find that this structure can be used as a general prototype of subwavelength light-driven actuators over a wide range of frequencies. This coupled structure can provide a strong and tunable torque, and can support different opto-mechanical modes, including uniform rotation, periodically variable rotation and damped oscillations. Our results suggest that chiral meta-atoms are good candidates for creating sub-wavelength motors or wrenches controlled by light.
Show PACS
03.75.Be Atom and neutron optics
42.79.-e Optical elements, devices, and systems

Guided-wave-coupled nitrogen vacancies in nanodiamond-doped photonic-crystal fibers

I. V. Fedotov, N. A. Safronov, Yu. A. Shandarov, A. A. Lanin, A. B. Fedotov, S. Ya. Kilin, K. Sakoda, M. O. Scully, and A. M. Zheltikov

Appl. Phys. Lett. 101, 031106 (2012); http://dx.doi.org/10.1063/1.4731762 (4 pages)

Online Publication Date: 17 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Zero-phonon-line (ZPL) emission of nitrogen vacancies (NVs) is coupled to the guided modes of solid- and hollow-core nanodiamond-doped photonic-crystal fibers (PCFs). Both types of PCFs are tailored toward enhancing ZPL emission coupling to the fiber modes. In solid-core PCFs, this involves enhancing the evanescent field of the waveguide modes supported by an ultrasmall fiber core. In hollow-core PCFs, the NV emission spectrum is matched with the transmission band of the fiber, controlled by the photonic bands of the fiber cladding.
Show PACS
42.81.Bm Fabrication, cladding, and splicing
42.70.Qs Photonic bandgap materials

Ultrafast semiconductor x-ray detector

K. L. Baker, R. E. Stewart, P. T. Steele, S. P. Vernon, and W. W. Hsing

Appl. Phys. Lett. 101, 031107 (2012); http://dx.doi.org/10.1063/1.4736411 (4 pages)

Online Publication Date: 17 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The National Ignition Campaign has the goal of developing a burning plasma platform producing up to ∼1019 neutrons in ∼20 picoseconds, ps. Diagnosis will require instruments operating with a time resolution of a few ps within this extremely large neutron flux environment. A diagnostic, which performs an ultrafast conversion of the x-ray signals into the optical regime, has been developed using a linearly chirped probe beam to measure the temporal history of the x-ray pulse. This diagnostic technique was tested on a laser-produced x-ray source and obtained a measurement of the full-width-at-half-maximum, FWHM, of the x-ray pulse of ∼7.2 ps.
Show PACS
29.40.Wk Solid-state detectors
52.70.La X-ray and γ-ray measurements

Buried graphene electrodes on GaN-based ultra-violet light-emitting diodes

Byung-Jae Kim, Chongmin Lee, Michael A. Mastro, Jennifer K. Hite, Charles R. Eddy, Jr., Fan Ren, Stephen J. Pearton, and Jihyun Kim

Appl. Phys. Lett. 101, 031108 (2012); http://dx.doi.org/10.1063/1.4733981 (3 pages) | Cited 2 times

Online Publication Date: 18 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report that the oxidation of graphene-based highly transparent conductive layers to AlGaN/GaN/AlGaN ultra-violet (UV) light-emitting diodes (LEDs) was suppressed by the use of SiNX passivation layers. Although graphene is considered to be an ideal candidate as the transparent conductive layer to UV-LEDs, oxidation of these layers at high operating temperatures has been an issue. The oxidation is initiated at the un-saturated carbon atoms at the edges of the graphene and reduces the UV light intensity and degrades the current-voltage (I-V) characteristics. The oxidation also can occur at defects, including vacancies. However, GaN-based UV-LEDs deposited with SiNX by plasma-enhanced chemical vapor deposition showed minimal degradation of light output intensity and I-V characteristics because the graphene-based UV transparent conductive layers were shielded from the oxygen molecules. This is a simple and effective approach for maintaining the advantages of graphene conducting layers as electrodes on UV-LEDs.
Show PACS
85.60.Jb Light-emitting devices

Complementary metal–oxide–semiconductor compatible high efficiency subwavelength grating couplers for silicon integrated photonics

Xiaochuan Xu, Harish Subbaraman, John Covey, David Kwong, Amir Hosseini, and Ray T. Chen

Appl. Phys. Lett. 101, 031109 (2012); http://dx.doi.org/10.1063/1.4737412 (4 pages) | Cited 1 time

Online Publication Date: 18 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate a through-etched grating coupler based on subwavelength nanostructure. The grating consists of arrays of 80 nm × 343 nm rectangular air holes, which can be patterned in a single lithography/etch. A peak coupling efficiency of 59% at 1551.6 nm and a 3 dB bandwidth of 60 nm are achieved utilizing the silicon-on-insulator platform with a 1 μm thick buried-oxide layer for transverse electric mode. The performance is comparable to gratings requiring much more complicated fabrication processes.
Show PACS
42.82.Et Waveguides, couplers, and arrays
42.79.Dj Gratings

Photocurrent spectroscopy of site-controlled pyramidal quantum dots

A. Mohan, L. Nevou, P. Gallo, B. Dwir, A. Rudra, E. Kapon, and J. Faist

Appl. Phys. Lett. 101, 031110 (2012); http://dx.doi.org/10.1063/1.4737426 (3 pages)

Online Publication Date: 18 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Intraband photocurrent spectroscopy of site-controlled pyramidal quantum dots by inserting them into the intrinsic region of n-i-n like quantum dot infrared photodetector structure is reported. The photovoltaic response is observed in the mid-infrared region. A peak responsivity of 0.4 mA/W at 120 meV (λ = 10 μm) is observed at 10 K at −2 V bias. The ability to engineer states in the conduction band of the QDs has been exploited to tune their photocurrent response from 10 μm to 18 μm with a narrow spectral width of Δλ/λ = 0.17.
Show PACS
72.40.+w Photoconduction and photovoltaic effects
73.21.La Quantum dots
73.63.Kv Quantum dots

Subpicosecond electron-hole recombination time and terahertz-bandwidth photoresponse in freestanding GaAs epitaxial mesoscopic structures

Martin Mikulics, Jie Zhang, John Serafini, Roman Adam, Detlev Grützmacher, and Roman Sobolewski

Appl. Phys. Lett. 101, 031111 (2012); http://dx.doi.org/10.1063/1.4737442 (4 pages)

Online Publication Date: 18 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present the ultrafast (THz-bandwidth) photoresponse from GaAs single-crystal mesoscopic structures, such as freestanding whiskers and platelets fabricated by the top-down technique, transferred onto a substrate of choice, and incorporated into a coplanar strip line. We recorded electrical transients as short as ∼600 fs from an individual whisker photodetector. Analysis of the frequency spectrum of the photoresponse electrical signal showed that, intrinsically, our device was characterized by an ∼150-fs carrier lifetime and an overall 320-fs response. The corresponding 3-dB frequency bandwidth was 1.3 THz—the highest bandwidth ever reported for a GaAs-based photodetector. Simultaneously, as high-quality, epitaxially grown crystals, our GaAs structures exhibited mobility values as high as ∼7300 cm2/V·s, extremely low dark currents, and ∼7% intrinsic detection efficiency, which, together with their experimentally measured photoresponse repetition time of ∼1 ps, makes them uniquely suitable for terahertz-frequency optoelectronic applications, ranging from ultrafast photon detectors and counters to THz-bandwidth optical-to-electrical transducers and photomixers.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)

Fast switchable grating based on orthogonal photo alignments of ferroelectric liquid crystals

A. K. Srivastava, Wei Hu, V. G. Chigrinov, A. D. Kiselev, and Yan-Qing Lu

Appl. Phys. Lett. 101, 031112 (2012); http://dx.doi.org/10.1063/1.4737642 (4 pages) | Cited 1 time

Online Publication Date: 18 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate a fast switchable grating based on ferroelectric liquid crystals and orthogonal planar alignment by means of photo alignments. Both 1D and 2D gratings have been constructed. The proposed diffracting element provides fast response time of around 20 μs, contrast of 7000:1 and high diffraction efficiency, at the electric field of 6 V/μm. The saturated electro-optical (EO) states up to very high frequency (≈5 kHz) are the real advantage of the proposed switchable grating, which opens several opportunities to improve the quality of existing devices and to find new applications.
Show PACS
42.70.Df Liquid crystals
42.79.Dj Gratings
77.84.-s Dielectric, piezoelectric, ferroelectric, and antiferroelectric materials

Direct generation of optical vortex pulses

Yongguang Zhao, Zhengping Wang, Haohai Yu, Shidong Zhuang, Huaijin Zhang, Xiaodong Xu, Jun Xu, Xinguang Xu, and Jiyang Wang

Appl. Phys. Lett. 101, 031113 (2012); http://dx.doi.org/10.1063/1.4737943 (4 pages) | Cited 2 times

Online Publication Date: 18 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate the direct generation of optical vortex pulses with stable energy and changeable orbital angular momentum. Single Laguerre-Gaussian (LG0,l) laser modes were directly generated using a laser diode with output intensity profile of doughnut distribution. With passive Q-switching, vortex pulses with stable energy were obtained. Moreover, the topological charge was changeable by variation of the pump power. By a mode-converter and second harmonic generation, the LG0,2l mode was identified. It can be proposed that this pulsed laser should have promising applications in various fields based on its compact structure, stable and high pulse energy, and changeable orbital angular momentum.
Show PACS
42.60.-v Laser optical systems: design and operation
42.55.Px Semiconductor lasers; laser diodes
42.55.Rz Doped-insulator lasers and other solid state lasers
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
02.50.-r Probability theory, stochastic processes, and statistics

Local rotational symmetry effects on Fano resonances with constant non-resonant transmission channel

Bo-Hong Li (李博宏), Houfang Liu (刘厚方), Fei Cheng (程飞), Jing Han (韩静), Hong Xiao (肖宏), Xiufeng Han (韩秀峰), Changzhi Gu (顾长志), and Xianggang Qiu (邱祥冈)

Appl. Phys. Lett. 101, 031114 (2012); http://dx.doi.org/10.1063/1.4737178 (4 pages)

Online Publication Date: 19 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Three kinds of 12-fold quasi-periodic subwavelength hole arrays have been designed using the same dodecahedral supercell arranged with different local rotational symmetries. Fano resonances associated with spoof surface plasmons in these structures have been studied by far-infrared transmission measurements. The resonant transmission channels of the lowest-order Fano resonance mode have been compared directly between these structures, benefitting from constant non-resonant transmission channel. It is found that the higher is the local rotational symmetry of the supercell array, the higher the transmission intensity and the narrower the linewidth of the Fano resonance.
Show PACS
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)
78.30.-j Infrared and Raman spectra
79.60.-i Photoemission and photoelectron spectra

Au nanoparticle-decorated graphene electrodes for GaN-based optoelectronic devices

Minhyeok Choe, Chu-Young Cho, Jae-Phil Shim, Woojin Park, Sung Kwan Lim, Woong-Ki Hong, Byoung Hun Lee, Dong-Seon Lee, Seong-Ju Park, and Takhee Lee

Appl. Phys. Lett. 101, 031115 (2012); http://dx.doi.org/10.1063/1.4737637 (4 pages) | Cited 3 times

Online Publication Date: 19 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We studied GaN-based optoelectronic devices such as light-emitting diodes (LEDs) and solar cells (SCs) with graphene electrodes. A decoration of Au nanoparticles (NPs) on multi-layer graphene films improved the electrical conductivity and modified the work function of the graphene films. The Au NP-decorated graphene film enhanced the current injection and electroluminescence of GaN-based LEDs through low contact resistance and improved the power conversion efficiency of GaN-based SCs through additional light absorption and energy band alignment. Our study will enhance the understanding of the role of Au NP-decorated graphene electrodes for GaN-based optoelectronic device applications.
Show PACS
85.60.Jb Light-emitting devices
85.65.+h Molecular electronic devices
88.40.hj Efficiency and performance of solar cells

Phase and coherence extraction from a phased vertical cavity laser array

Matthew T. Johnson, Dominic F. Siriani, Joshua D. Sulkin, and Kent D. Choquette

Appl. Phys. Lett. 101, 031116 (2012); http://dx.doi.org/10.1063/1.4736406 (4 pages)

Online Publication Date: 19 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The relative coherence and phase are extracted from two-element, coherently coupled, vertical cavity surface emitting laser arrays. The array elements are defined optically by a photonic crystal pattern and electrically by ion implantation. We obtain the near and far fields experimentally under varying current injection. The Fraunhofer approximation is used to simulate propagation from the near to far field. The phase and coherence are extracted as fitting parameters to match the experimental and propagated far field patterns. The phase and coherence will aid in future array designs and in elucidating the phase-shifting mechanism.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.70.Qs Photonic bandgap materials

Tuning the wavelength of amplified spontaneous emission coupled to localized surface plasmon

S. Murai, Y. Tokuda, K. Fujita, and K. Tanaka

Appl. Phys. Lett. 101, 031117 (2012); http://dx.doi.org/10.1063/1.4736408 (3 pages)

Online Publication Date: 19 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Amplified spontaneous emissions (ASEs) with a tuned wavelength have been observed in a thin film composite made by spin-coating a dye-doped polymer layer (thickness ∼80 nm) on Ag nanoparticles deposited on a SiO2 substrate. The samples having a varied wavelength of the localized surface plasmon resonance (LSPR) are excited with second harmonic pulses from a Nd3+ doped yttrium aluminum garnet laser. When the pump energy exceeds a threshold, a spectrally narrow peak appears on a broad emission from dye molecules with a nonlinear increase in emission intensity, indicating an onset of ASE. It is found that the peak wavelength of ASE shifts with the change of the wavelength of LSPR.
Show PACS
78.45.+h Stimulated emission
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)
73.22.Lp Collective excitations

Reduction of persistent photoconductivity in ZnO thin film transistor-based UV photodetector

Pavel Ivanoff Reyes, Chieh-Jen Ku, Ziqing Duan, Yi Xu, Eric Garfunkel, and Yicheng Lu

Appl. Phys. Lett. 101, 031118 (2012); http://dx.doi.org/10.1063/1.4737648 (4 pages)

Online Publication Date: 19 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report a ZnO-based thin film transistor UV photodetector with a back gate configuration. The thin-film transistor (TFT) aspect ratio W/L is 150 μm/5 μm and has a current on-off ratio of 1010. The detector shows UV-visible rejection ratio of 104 and cut-off wavelength of 376 nm. The device has low dark current of 5 × 10−14 A. The persistent photoconductivity is suppressed through oxygen plasma treatment of the channel surface which significantly reduces the density of oxygen vacancy confirmed by XPS measurements. The proper gate bias-control further reduces recovery time. The UV-TFT configuration is particularly suitable for making large-area imaging arrays.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
85.30.Tv Field effect devices

White metal-like omnidirectional mirror from porous silicon dielectric multilayers

A. David Ariza-Flores, L. M. Gaggero-Sager, and V. Agarwal

Appl. Phys. Lett. 101, 031119 (2012); http://dx.doi.org/10.1063/1.4738765 (3 pages)

Online Publication Date: 20 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the design and fabrication of the complete visible range omnidirectional mirror, with a dielectric multilayered structure based on porous silicon (PS). The refractive index profile consisted of Bragg type chirped layers with an increasing thicknesses modulated by a potential envelop function f(x) = Cxk. The omnidirectional photonic band gap (OPBG) was measured from 396 to 805 nm, with more than 95% of the reflectivity, for 8° and 68°. The theoretical simulations based on the transfer matrix method along with a photographic sequence of the sample confirmed the OPBG for higher incident angles. It was enhanced by a factor of 19 as compared to the last reported visible region OPBG by PS dielectric multilayered structure.
Show PACS
42.79.Bh Lenses, prisms and mirrors
42.82.Cr Fabrication techniques; lithography, pattern transfer
42.15.Eq Optical system design
42.70.Qs Photonic bandgap materials
back to top
RSS Feeds

Snap-in dynamics of single particles to water drops

Longquan Chen, Lars-Oliver Heim, Dmytro S. Golovko, and Elmar Bonaccurso

Appl. Phys. Lett. 101, 031601 (2012); http://dx.doi.org/10.1063/1.4737210 (5 pages) | Cited 1 time

Online Publication Date: 16 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The interaction between solid particles and gas-liquid interfaces is relevant in technological applications. Former studies did focus on detachment-dynamics of particles from thin liquid films or on attachment-dynamics of particles to gas bubbles. Here, we investigated snap-in dynamics of individual micron-sized particles to water drops by means of the colloidal probe technique. The snap-in time (∼0.1 ms) and the snap-in force of hydrophilic and hydrophobic particles were measured. The snap-in time increased with particle size regardless of wettability. The snap-in force increased with particle size and wettability. We show that the snap-in dynamics is dominated by capillarity and inertia.
Show PACS
47.55.D- Drops and bubbles
47.55.nb Capillary and thermocapillary flows
68.08.Bc Wetting
68.15.+e Liquid thin films
82.70.Dd Colloids

Critical influence of target-to-substrate distance on conductive properties of LaGaO3/SrTiO3 interfaces deposited at 10−1 mbar oxygen pressure

C. Aruta, S. Amoruso, G. Ausanio, R. Bruzzese, E. Di Gennaro, M. Lanzano, F. Miletto Granozio, Muhammad Riaz, A. Sambri, U. Scotti di Uccio, and X. Wang

Appl. Phys. Lett. 101, 031602 (2012); http://dx.doi.org/10.1063/1.4737650 (5 pages) | Cited 1 time

Online Publication Date: 18 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We investigate pulsed laser deposition of LaGaO3/SrTiO3 at 10−1 mbar oxygen background pressure, demonstrating the critical effect of the target-to-substrate distance, dTS, on the interface sheet resistance, Rs. The interface turns from insulating to metallic by progressively decreasing dTS. The analysis of the LaGaO3 plume evidences the important role of the plume propagation dynamics on the interface properties. These results demonstrate the growth of conducting interfaces at an oxygen pressure of 10−1 mbar, an experimental condition where a well-oxygenated heterostructures with a reduced content of oxygen defects is expected.
Show PACS
72.20.Fr Low-field transport and mobility; piezoresistance
72.80.Sk Insulators
81.15.Fg Pulsed laser ablation deposition
61.72.jd Vacancies
back to top
RSS Feeds

One-dimensional stringlike cooperative migration of lithium ions in an ultrafast ionic conductor

M. Xu, J. Ding, and E. Ma

Appl. Phys. Lett. 101, 031901 (2012); http://dx.doi.org/10.1063/1.4737397 (3 pages) | Cited 1 time

Online Publication Date: 16 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In the recently developed ultrafast Li-ion conductor, Li10GeP2S12, our ab initio and molecular dynamics simulations have revealed a unique Li ion transport mechanism. The Li ions are discovered to migrate in a highly correlated fashion, stemming from the large Coulombic interaction between the mobile ions. The stringlike cooperative ionic motion is found to entail a rather low energy barrier, contributing to the unusually high ionic conductivity of this solid-state electrolyte. Such a collective migration mechanism may also be operative in other Li-ion battery electrolytes with high concentrations of mobile Li ions.
Show PACS
66.30.hd Ionic crystals
82.45.Gj Electrolytes

Stochastic optical active rheology

Hyungsuk Lee, Yongdae Shin, Sun Taek Kim, Ellis L. Reinherz, and Matthew J. Lang

Appl. Phys. Lett. 101, 031902 (2012); http://dx.doi.org/10.1063/1.4737159 (4 pages) | Cited 1 time

Online Publication Date: 17 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate a stochastic based method for performing active rheology using optical tweezers. By monitoring the displacement of an embedded particle in response to stochastic optical forces, a rapid estimate of the frequency dependent shear moduli of a sample is achieved in the range of 10−1–103 Hz. We utilize the method to probe linear viscoelastic properties of hydrogels at varied cross-linker concentrations. Combined with fluorescence imaging, our method demonstrates non-linear changes of bond strength between T cell receptors and an antigenic peptide due to force-induced cell activation.
Show PACS
83.85.Ei Optical methods; rheo-optics
42.50.Wk Mechanical effects of light on material media, microstructures and particles
87.15.Fh Bonding; mechanisms of bond breakage
82.70.Gg Gels and sols
83.60.Bc Linear viscoelasticity

An inside-out Eaton lens made of H-fractal metamaterials

Qiannan Wu, Xiaoyi Feng, Ruirui Chen, Chendong Gu, Sucheng Li, Hui Li, Yadong Xu, Yun Lai, Bo Hou, Huanyang Chen, and Yunhui Li

Appl. Phys. Lett. 101, 031903 (2012); http://dx.doi.org/10.1063/1.4737411 (4 pages) | Cited 1 time

Online Publication Date: 17 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report an experiment on an inside-out Eaton lens fabricated using H-fractal metamaterials, copper printed on printed circuit boards in H-fractal patterns. The lens can perform good imaging functionality with both sources and images inside the vacuum core. The H-fractal metamaterials also provide design technique to achieve refractive index ranging in [0,1] with little loss in microwave spectrum. Excellent agreements between numerical and experimental results have been demonstrated.
Show PACS
42.79.Bh Lenses, prisms and mirrors
42.82.Cr Fabrication techniques; lithography, pattern transfer
42.70.-a Optical materials

Silicon edges as one-dimensional waveguides for dispersion-free and supersonic leaky wedge waves

Alexey M. Lomonosov, Peter Hess, and Andreas P. Mayer

Appl. Phys. Lett. 101, 031904 (2012); http://dx.doi.org/10.1063/1.4737011 (4 pages) | Cited 1 time

Online Publication Date: 17 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Acoustic waves guided by the cleaved edge of a Si(111) crystal were studied using a laser-based angle-tunable transducer for selectively launching isolated wedge or surface modes. A supersonic leaky wedge wave and the fundamental wedge wave were observed experimentally and confirmed theoretically. Coupling of the supersonic wave to shear waves is discussed, and its leakage into the surface acoustic wave was observed directly. The velocity and penetration depth of the wedge waves were determined by contact-free optical probing. Thus, a detailed experimental and theoretical study of linear one-dimensional guided modes in silicon is presented.
Show PACS
68.35.Iv Acoustical properties
43.20.Mv Waveguides, wave propagation in tubes and ducts
43.35.Pt Surface waves in solids and liquids
Page 1 of 5 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close