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
Return to All Sections
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

Ge2Sb2Te5 phase-change films on polyimide substrates by pulsed laser deposition

Hongbing Lu, Erik Thelander, Jürgen W. Gerlach, Dietmar Hirsch, Ulrich Decker, and Bernd Rauschenbach

Appl. Phys. Lett. 101, 031905 (2012); http://dx.doi.org/10.1063/1.4737410 (4 pages) | Cited 1 time

Online Publication Date: 18 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Growth of Ge2Sb2Te5 phase-change films on flexible polyimide substrates by pulsed laser deposition (PLD) is demonstrated. The effect of annealing temperature on the crystalline nature of the films was studied. A decrease of (200) lattice plane distance with the increase of annealing temperature was revealed for the films grown on both polyimide and Si substrates, which was related to tensile stress in the crystallized films. Optical reflectivity measurements showed a high reflectivity contrast between full crystalline and amorphous films. The results indicate an excellent potential for applications of these PLD-deposited Ge2Sb2Te5 films on flexible polyimide substrates in optical data storage.
Show PACS
78.66.Nk Insulators
81.15.Fg Pulsed laser ablation deposition
81.40.Gh Other heat and thermomechanical treatments
68.55.-a Thin film structure and morphology

Type-II GaSb/GaAs coupled quantum rings: Room-temperature luminescence enhancement and recombination lifetime elongation for device applications

Wei-Hsun Lin, Kai-Wei Wang, Shu-Wei Chang, Min-Hsiung Shih, and Shih-Yen Lin

Appl. Phys. Lett. 101, 031906 (2012); http://dx.doi.org/10.1063/1.4737443 (4 pages) | Cited 2 times

Online Publication Date: 18 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Type-II GaSb/GaAs coupled quantum rings have exhibited two-order-of-magnitude luminescence enhancement and ten-times elongation of recombination lifetime at room temperature as compared with regular rings. The longer lifetime suggests that a significant amount of electrons are confined in coupled rings rather than simply leaking away. These phenomena indicate that type-II nanostructures can be potentially utilized for room-temperature luminescence and carrier storage applications.
Show PACS
78.55.Cr III-V semiconductors
78.67.Hc Quantum dots
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
73.63.Kv Quantum dots

Light amplification in zero-index metamaterial with gain inserts

Weiren Zhu, Ivan D. Rukhlenko, and Malin Premaratne

Appl. Phys. Lett. 101, 031907 (2012); http://dx.doi.org/10.1063/1.4737643 (4 pages) | Cited 6 times

Online Publication Date: 18 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The concept of light amplification in a system of zero-index metamaterial with gain inserts is studied. We demonstrate that the radiation from a point source embedded in the system can be effectively amplified and the net gain is independent of the positions of gain inserts and the source. We further investigate how the net gain grows with the imaginary part of the inserts’ permittivities and find that it saturates when the imaginary part is sufficiently large. It is also shown that the efficiency of amplification is significantly reduced when lossy inserts are introduced into the system.
Show PACS
42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)

Longitudinal optical phonon-plasmon coupled modes of degenerate Al-doped ZnO films

K. Ding, Q. C. Hu, W. W. Lin, J. K. Huang, and F. Huang

Appl. Phys. Lett. 101, 031908 (2012); http://dx.doi.org/10.1063/1.4737647 (5 pages)

Online Publication Date: 18 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have investigated the interaction between carriers and polar phonons by using Raman scattering spectroscopy in highly conductive Al-doped ZnO films grown by metalorganic chemical vapor deposition. Different from the longitudinal optical phonon-plasmon coupled modes (LOPPCM) observed in nondegenerate ZnO, an A1(LO)-like mode appears at the low frequency side of the uncoupled A1(LO) mode, and it monotonically shifts to higher frequencies and approaches to the uncoupled A1(LO) mode as Al composition increases. Based on line shape calculations, the A1(LO)-like mode is assigned to the large wave-vector LOPPCM arising from nonconserving scattering dominated by the Al impurity-induced Fröhlich mechanism. Benefiting from the nonmonotonic Al composition dependence of the electron density, it is revealed that the LOPPCM depends mainly on the doping level but not the carrier concentration.
Show PACS
68.55.ag Semiconductors
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
78.30.Fs III-V and II-VI semiconductors
78.66.Hf II-VI semiconductors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
61.72.uj III-V and II-VI semiconductors

Electrical and thermoelectric properties of single-wall carbon nanotube doped Bi2Te3

Y. Zhang, X. L. Wang, W. K. Yeoh, R. K. Zheng, and C. Zhang

Appl. Phys. Lett. 101, 031909 (2012); http://dx.doi.org/10.1063/1.4737898 (4 pages)

Online Publication Date: 18 July 2012

Full Text: Read Online (HTML) | Download PDF


See Also: Publisher's Note

Show Abstract
The effects of single-wall carbon nanotube (SWCNT) doping in n-type Bi2Te3 bulk samples on the electrical and thermal transport properties have been studied. Bi2Te3 samples doped with 0–5 wt. % SWCNTs were fabricated using solid state reaction and investigated using x-ray diffraction, transmission electron microscopy, and magneto transport measurements. Results show that the 0.5% doping results in the significant enhancement of the Seebeck coefficience to as high as −231.8 μV/K, giant magneto resistance of up to 110%, reduction of thermal conductivity, and change of sign of the Seebeck coefficient from n to p type depending on the doping level and temperature. The figure of merit, ZT, of the optimum SWCNT doped Bi2Te3 was increased by 25%–40% over a wide temperature range compared to the undoped sample.
Show PACS
72.20.Pa Thermoelectric and thermomagnetic effects
81.20.Ev Powder processing: powder metallurgy, compaction, sintering, mechanical alloying, and granulation
61.72.up Other materials
66.70.Lm Other systems such as ionic crystals, molecular crystals, nanotubes, etc.
61.66.Fn Inorganic compounds
72.20.My Galvanomagnetic and other magnetotransport effects

A realistic design of three-dimensional full cloak at terahertz frequencies

Yongjun Bao, Cheng He, Fan Zhou, Colin Stuart, and Cheng Sun

Appl. Phys. Lett. 101, 031910 (2012); http://dx.doi.org/10.1063/1.4735133 (4 pages) | Cited 1 time

Online Publication Date: 19 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This paper presents a realistic design of a three-dimensional invisibility full cloak device at Terahertz frequency, consisting of radially arranged polymer slabs covered with III-V semiconductor materials featuring Drude-like resonance. By applying high order optical transformation, it is possible to constrain the semiconductor layer of constant thickness for the convenience in practical fabrication. The anisotropic and spatially variant material constants are realized by adjusting the filling ratio of the polymer slabs. Such a structure can be readily fabricated using high-aspect ratio three-dimensional microfabrication of polymeric slabs in combine with conformal deposition of the semiconductor cladding layer.
Show PACS
42.70.Jk Polymers and organics
42.79.-e Optical elements, devices, and systems

Plasmonic mediated nucleation of resonant nano-cavities

V. G. Karpov, M. Nardone, and A. V. Subashiev

Appl. Phys. Lett. 101, 031911 (2012); http://dx.doi.org/10.1063/1.4737654 (4 pages) | Cited 1 time

Online Publication Date: 19 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We show that the energy required for nucleation can be efficiently supplied by the electromagnetic field in resonance with plasmonic oscillations of a nucleus, and the field frequency dictates its strongly anisotropic resonant shape. The predicted effect is especially strong for nucleation of pancake shaped nano-cavities in skin depth metallic layers. This significant modification of nucleation physics can have important implications in nano-photonics and optical recording.
Show PACS
42.79.-e Optical elements, devices, and systems
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)
41.20.-q Applied classical electromagnetism

Realization of compressively strained GaN films grown on Si(110) substrates by inserting a thin AlN/GaN superlattice interlayer

X. Q. Shen, T. Takahashi, H. Kawashima, T. Ide, and M. Shimizu

Appl. Phys. Lett. 101, 031912 (2012); http://dx.doi.org/10.1063/1.4737874 (4 pages)

Online Publication Date: 19 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We investigate the strain properties of GaN films grown by plasma-assisted molecular beam epitaxy on Si(110) substrates. It is found that the strain of the GaN film can be converted from a tensile to a compressive state simply by inserting a thin AlN/GaN superlattice structure (SLs) within the GaN film. The GaN layers seperated by the SLs can have different strain states, which indicates that the SLs plays a key role in the strain modulation during the growth and the cooling down processes. Using this simple technique, we grow a crack-free GaN film exceeding 2-μm-thick. The realization of the compressively strained GaN film makes it possible to grow thick GaN films without crack generation on Si substrates for optic and electronic device applications.
Show PACS
68.55.ag Semiconductors
52.77.-j Plasma applications
68.65.Cd Superlattices
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy

Substrate effect on the room-temperature ferromagnetism in un-doped ZnO films

Peng Zhan, Weipeng Wang, Zheng Xie, Zhengcao Li, Zhengjun Zhang, Peng Zhang, Baoyi Wang, and Xingzhong Cao

Appl. Phys. Lett. 101, 031913 (2012); http://dx.doi.org/10.1063/1.4737881 (4 pages) | Cited 2 times

Online Publication Date: 19 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Room-temperature ferromagnetism was achieved in un-doped ZnO films on silicon and quartz substrates. Photoluminescence measurement and positron annihilation analysis suggested that the ferromagnetism was originated from singly occupied oxygen vacancies (roughly estimated as ∼0.55 μB/vacancy), created in ZnO films by annealing in argon. The saturated magnetization of ZnO films was enhanced from ∼0.44 emu/g (on quartz) to ∼1.18 emu/g (on silicon) after annealing at 600 °C, as silicon acted as oxygen getter and created more oxygen vacancies in ZnO films. This study clarified the origin of ferromagnetism in un-doped ZnO and provides an idea to enhance the ferromagnetism.
Show PACS
75.70.Ak Magnetic properties of monolayers and thin films
78.55.Et II-VI semiconductors
78.70.Bj Positron annihilation
81.40.Gh Other heat and thermomechanical treatments
75.50.Dd Nonmetallic ferromagnetic materials
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close