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20 May 2013

Volume 102, Issue 20 (partial)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 102, 203301 (2013); http://dx.doi.org/10.1063/1.4804595 (4 pages)

Michael Salinas and Marcus Halik
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Enhanced photon-generated carrier extraction from Si nanostructure under additional infrared light irradiation

Wei Yu, Yanmei Xu, Huimin Li, Jin Wang, Guangsheng Fu, and Wanbing Lu

Appl. Phys. Lett. 102, 201101 (2013); http://dx.doi.org/10.1063/1.4807281 (4 pages)

Online Publication Date: 20 May 2013

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Recombination and trapping effect in quantum dots are large barriers to efficient photon-generated carrier extraction. In this paper, Infrared (IR)-assisted carrier extraction in a Si/SiO2 multiple quantum well is demonstrated. Operated at reverse bias, enhanced photoresponse from 300 to 700 nm is observed. External quantum efficiency nearly 200% is obtained when both visible light and IR are added. The enhancement is attributed to potential modulation by photo-illumination. A theoretical model including three processes is presented to explain this conclusion. The secondary light source IR could excite trapped carriers from the defects at the Si/SiO2 interface, improving extraction efficiency.
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82.50.Hp Processes caused by visible and UV light

Dopant migration effects in terahertz quantum cascade lasers

C. Deutsch, H. Detz, M. Krall, M. Brandstetter, T. Zederbauer, A. M. Andrews, W. Schrenk, G. Strasser, and K. Unterrainer

Appl. Phys. Lett. 102, 201102 (2013); http://dx.doi.org/10.1063/1.4805040 (4 pages)

Online Publication Date: 20 May 2013

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We demonstrate that dopant migration and the resulting impurity scattering can strongly influence the performance of GaAs/Al0.15Ga0.85As terahertz quantum cascade lasers. A nominally symmetric structure allows us to compare the negative and positive bias behavior of the very same device. Dopants, migrated towards the upper laser level during sample growth, degrade the lasing performance due to enhanced impurity scattering rates. The consequences are a higher threshold current (+30%) and reduced optical output power (–29%) in the affected operating direction. This polarity dependent performance is reversed in an asymmetrically doped sample, which imitates the migration of dopants against the growth direction.
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42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems
85.40.Ry Impurity doping, diffusion and ion implantation technology
61.72.U- Doping and impurity implantation

Single InAs quantum dot coupled to different “environments” in one wafer for quantum photonics

Ying Yu, Xiang-Jun Shang, Mi-Feng Li, Guo-Wei Zha, Jian-Xing Xu, Li-Juan Wang, Guo-Wei Wang, Hai-Qiao Ni, Xiuming Dou, Baoquan Sun, and Zhi-Chuan Niu

Appl. Phys. Lett. 102, 201103 (2013); http://dx.doi.org/10.1063/1.4807502 (4 pages)

Online Publication Date: 20 May 2013

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Self assembled small InAs quantum dots (SQDs) were formed in various densities and environments using gradient InAs deposition on a non-rotating GaAs substrate. Two SQD environments (SQD I and SQD II) were characterized. SQD I featured SQDs surrounded by large QDs, and SQD II featured individual SQDs in the wetting layer (WL). Micro-photoluminescence of single QDs embedded in a cavity under various excitation powers and electric fields gave insight into carrier transport processes. Potential fluctuations of the WL in SQD II, induced by charge redistribution, show promise for charge-tunable QD devices; SQD I shows higher luminescence intensity as a single-photon source.
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78.67.Hc Quantum dots
81.07.Ta Quantum dots
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
73.63.Kv Quantum dots
78.55.Cr III-V semiconductors
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Young-Lippmann equation revisited for nano-suspensions

Daniel Orejon, Khellil Sefiane, and Martin E. R. Shanahan

Appl. Phys. Lett. 102, 201601 (2013); http://dx.doi.org/10.1063/1.4807120 (3 pages)

Online Publication Date: 20 May 2013

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We present the results of an experimental study investigating electrowetting effects in nano-suspension drops. Wetting of sessile drops of titanium oxide (TiO2) nano-particles dispersed in deionised water was studied under a DC voltage potential. The presence of nano-particles is found to further enhance spreading of drops when a DC potential is applied. Results are explained based on the change in interfacial energy induced by nano-particle adsorption at the solid-liquid interface. An amendment of the Young-Lippmann equation accounting for the presence of nano-particles is proposed. The electrowetting expression proposed is validated against the experimental data for substrates with various dielectric thicknesses.
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82.70.Kj Emulsions and suspensions
68.08.Bc Wetting
68.43.Mn Adsorption kinetics
68.43.-h Chemisorption/physisorption: adsorbates on surfaces
81.07.Bc Nanocrystalline materials
61.46.Df Structure of nanocrystals and nanoparticles ("colloidal" quantum dots but not gate-isolated embedded quantum dots)

Fabrication and scanning tunneling microscopy characterization of suspended monolayer graphene on periodic Si nanopillars

Xin Zhao, Xiaofang Zhai, Aidi Zhao, Bing Wang, and J. G. Hou

Appl. Phys. Lett. 102, 201602 (2013); http://dx.doi.org/10.1063/1.4807139 (4 pages)

Online Publication Date: 20 May 2013

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We present the fabrication and scanning tunneling microscopy (STM) characterization of suspended monolayer graphene (SMG) on periodic Si nanostructure. Monolayer graphene (MG) was grown on Cu foils by chemical vapor deposition (CVD) and transferred onto a Si substrate with etched array of periodic nanopillars, obtaining partly suspended MG. Low-temperature STM characterization was performed on the suspension area of the MG with atomic resolution images obtained. The scanning tunneling spectroscopy of SMG shows a nonlinear behavior near the Fermi level (EF), which is attributed to the Dirac cone reshaped by electron-electron interaction.
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68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)
61.48.-c Structure of fullerenes and related hollow and planar molecular structures
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
82.70.Kj Emulsions and suspensions
81.16.-c Methods of micro- and nanofabrication and processing

Investigation of the release of Si from SiO2 during the formation of manganese/ruthenium barrier layers

A. P. McCoy, P. Casey, J. Bogan, C. Byrne, and G. Hughes

Appl. Phys. Lett. 102, 201603 (2013); http://dx.doi.org/10.1063/1.4807428 (4 pages)

Online Publication Date: 20 May 2013

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The thermodynamic and structural stability of ruthenium-manganese diffusion barriers on SiO2 is assessed. A ∼2 nm film composed of partially oxidized manganese (MnOx where x < 1) was deposited on a 3 nm thick Ru film and the Mn-MnOx/Ru/SiO2 structure was subsequently thermally annealed. X-ray photoelectron spectroscopy and secondary ion mass spectroscopy studies suggest the release and upward diffusion of Si from the dielectric substrate as a result of manganese-silicate formation at the Ru/SiO2 interface. The migration of Si up through the Ru film results in further manganese-silicate formation upon its interaction with the Mn-MnOx deposited layer.
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66.30.Ny Chemical interdiffusion; diffusion barriers
79.60.Jv Interfaces; heterostructures; nanostructures
81.40.Gh Other heat and thermomechanical treatments
82.80.Ms Mass spectrometry (including SIMS, multiphoton ionization and resonance ionization mass spectrometry, MALDI)
82.80.Pv Electron spectroscopy (X-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.)
65.40.G- Other thermodynamical quantities
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Experimental realization of reflection-type periodic diffraction correlation imaging

Hu Li, Yinzuo Zhang, Jianhong Shi, and Guihua Zeng

Appl. Phys. Lett. 102, 201901 (2013); http://dx.doi.org/10.1063/1.4807441 (4 pages)

Online Publication Date: 20 May 2013

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We demonstrate the periodic diffraction correlation imaging (PDCI) of a reflective object using only one array detector to achieve simpler setups of ghost imaging: no beam-splitter is needed, and only one detector is utilized. Multiple reference beams with a same pattern of the signal beam are generated in the PDCI, which makes PDCI realize high-order imaging more easily than conventional ghost imaging. Further, the influence of background noise on the imaging quality in PDCI can be reduced by the image merging technology proposed in this letter.
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42.30.Va Image forming and processing
42.79.Dj Gratings
85.60.Gz Photodetectors (including infrared and CCD detectors)
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All-optical measurement of vertical charge carrier transport in mid-wave infrared InAs/GaSb type-II superlattices

B. V. Olson, L. M. Murray, J. P. Prineas, M. E. Flatté, J. T. Olesberg, and T. F. Boggess

Appl. Phys. Lett. 102, 202101 (2013); http://dx.doi.org/10.1063/1.4807433 (4 pages)

Online Publication Date: 20 May 2013

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Time-resolved differential transmission measurements were used to investigate vertical charge carrier transport in mid-wave infrared InAs/GaSb type-II superlattices (T2SLs). By optically generating excess carriers near one end of the mid-wave T2SL and measuring the transit time to a thin, lower-bandgap T2SL at the other end, the time-of-flight of vertically diffusing carriers was measured. Through investigation of both unintentionally doped and p-type T2SLs, the vertical hole and electron diffusion coefficients were measured to be 0.04 ± 0.03 cm2/s and 4.7 ± 0.5 cm2/s, corresponding to vertical mobilities of 6 ± 5 cm2/Vs and 700 ± 80 cm2/Vs, respectively, at a temperature of 77 K.
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73.63.-b Electronic transport in nanoscale materials and structures
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
78.67.Pt Multilayers; superlattices; photonic structures; metamaterials
78.47.D- Time resolved spectroscopy (>1 psec)
72.20.Fr Low-field transport and mobility; piezoresistance
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
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Magnetic tunnel junctions with Al2O3 tunnel barriers prepared by atomic layer deposition

Xinfei Liu and Jing Shi

Appl. Phys. Lett. 102, 202401 (2013); http://dx.doi.org/10.1063/1.4807132 (4 pages)

Online Publication Date: 20 May 2013

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Uniform Al2O3 tunnel barriers are fabricated with atomic layer deposition. The tunneling magnetoresistance in optimized Al2O3-based magnetic tunnel junctions is studied as a function of temperature in comparison with SrTiO3-based tunnel devices having the same La0.7Sr0.3MnO3 and Co electrodes. The junction resistance peaks at the onset temperature of the tunneling magnetoresistance which lies below the metal-insulator transition temperature of the La0.7Sr0.3MnO3 film. These results suggest a lower interface metal-insulator and ferromagnetic ordering temperature.
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72.20.My Galvanomagnetic and other magnetotransport effects
75.47.Pq Other materials
71.30.+h Metal-insulator transitions and other electronic transitions
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Exchange-spring like magnetic behavior of the tetragonal Heusler compound Mn2FeGa as a candidate for spin-transfer torque

Teuta Gasi, Ajaya K. Nayak, Jürgen Winterlik, Vadim Ksenofontov, Peter Adler, Michael Nicklas, and Claudia Felser

Appl. Phys. Lett. 102, 202402 (2013); http://dx.doi.org/10.1063/1.4807427 (4 pages)

Online Publication Date: 20 May 2013

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We report structural, magnetic, and Mössbauer studies of the Heusler compound Mn2FeGa. Theoretical calculations predict that a tetragonal phase in Mn2FeGa could be an interesting candidate for spin torque transfer applications due to the presence of perpendicular magnetic anisotropy. Experimentally, we found that Mn2FeGa crystallizes in a tetragonal structure after annealing at low temperatures ( ≤ 400 °C), whereas, it becomes pseudocubic for higher annealing temperatures. The sample annealed at 400 °C shows a high Curie temperature of 650 K and a hard-magnetic behavior. We observed a nonsaturating and exchange-spring type of hysteresis loops, which indicates that the sample contains two different magnetic states. The Mössbauer measurements clearly support the structural and magnetic data. All these properties make the material a potential candidate for spintronic devices, especially in thin films with perpendicular magnetic anisotropy.
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75.30.Et Exchange and superexchange interactions
75.30.Gw Magnetic anisotropy
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
76.80.+y Mössbauer effect; other γ-ray spectroscopy
61.66.Dk Alloys
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Superconductor/ferromagnet heterostructures exhibit potential for significant reduction of hysteretic losses

Philipp Krüger, Francesco Grilli, Michal Vojenčiak, Victor M. R. Zermeño, Eduard Demencik, and Stefania Farinon

Appl. Phys. Lett. 102, 202601 (2013); http://dx.doi.org/10.1063/1.4807136 (4 pages)

Online Publication Date: 20 May 2013

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First experimental observations of the ferromagnetic shielding effect in high-Tc superconducting coated conductors were carried out. Experimental results were compared to simulations calling upon finite-element calculations based on the H-formulation of Maxwell equations to model superconducting strips with ferromagnetic shields. Samples of copper-stabilized coated conductors were electroplated with nickel shields and afterwards characterized. Both externally applied oscillating transverse magnetic fields as well as transport currents were studied. Having observed promising gains with respect to the reduction of ac losses in both cases, we further investigated the potential of ferromagnetic shielding. The numerical model was able to reproduce and also predict experimental results very well and will serve as an indispensable tool to determine the potential of soft ferromagnetic materials to significantly reduce hysteretic losses.
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74.72.-h Cuprate superconductors
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
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Resonance enhancement of difference-frequency generation through localized surface plasmon excitation

Xu Fang, Shin Yaginuma, Wakana Kubo, and Takuo Tanaka

Appl. Phys. Lett. 102, 203101 (2013); http://dx.doi.org/10.1063/1.4807169 (4 pages)

Online Publication Date: 20 May 2013

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We report the experimental observation of difference-frequency generation in gold nanoparticles under localized surface plasmon excitation. A zero-delay peak is detected in the differential transmission signal for a gold nanoparticle film with a MgF2 overlayer, showing that the energy transfer from pump light to probe light through the difference-frequency generation is resonantly enhanced by the excitation. This peak of differential transmission decreases in strength with higher probe fluences. Both the enhancement and the power dependence of the difference-frequency generation are explained by modeling the localized surface plasmons as a nonlinear Lorentz resonator.
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42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)
73.22.Lp Collective excitations
78.66.Bz Metals and metallic alloys

Core-shell magnetic exchange model for Co3O4 nanowires

Lan Chen, Yurong Yang, and Xiangkang Meng

Appl. Phys. Lett. 102, 203102 (2013); http://dx.doi.org/10.1063/1.4807393 (5 pages)

Online Publication Date: 20 May 2013

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First-principles calculations are performed to investigate the magnetic properties of Co3O4 nanowires. A microscopic core-shell magnetic exchange model, including intra-core, intra-plane, core-shell (core-plane), and plane-plane (shell-shell) interactions, is proposed. The sign of magnetic exchange constants (ferromagnetic or antiferromagnetic coupling) for the four interactions is computed and discussed with respect to nanowire diameter. Competition between plane-plane and core-plane interactions is found in nanowire larger than 15.4 Å. The four magnetic interactions and their competition in the nanostructures give an explanation of exchange bias effect, two order temperatures, spin-glass behavior, and magnetic fingerprints found in core-shell structures experimentally.
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75.30.Et Exchange and superexchange interactions
75.50.Dd Nonmetallic ferromagnetic materials
75.50.Ee Antiferromagnetics
75.50.Tt Fine-particle systems; nanocrystalline materials
81.07.Gf Nanowires
75.10.Nr Spin-glass and other random models

Negative compressibility observed in graphene containing resonant impurities

X. L. Chen, L. Wang, W. Li, Y. Wang, Y. H. He, Z. F. Wu, Y. Han, M. W. Zhang, W. Xiong, and N. Wang

Appl. Phys. Lett. 102, 203103 (2013); http://dx.doi.org/10.1063/1.4807394 (4 pages)

Online Publication Date: 20 May 2013

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We observed negative compressibility in monolayer graphene containing resonant impurities under different magnetic fields. Hydrogenous impurities were introduced into graphene by electron beam (e-beam) irradiation. Resonant states located in the energy region of ±0.04 eV around the charge neutrality point were probed in e-beam-irradiated graphene capacitors. Theoretical results based on tight-binding and Lifshitz models agreed well with experimental observations of graphene containing a low concentration of resonant impurities. The interaction between resonant states and Landau levels was detected by varying the applied magnetic field. The interaction mechanisms and enhancement of the negative compressibility in disordered graphene are discussed.
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71.55.Ht Other nonmetals
71.70.Di Landau levels
81.40.Lm Deformation, plasticity, and creep
61.48.Gh Structure of graphene
61.80.Fe Electron and positron radiation effects
71.15.Ap Basis sets (LCAO, plane-wave, APW, etc.) and related methodology (scattering methods, ASA, linearized methods, etc.)

High-resolution chemical imaging of gold nanoparticles using hard x-ray ptychography

R. Hoppe, J. Reinhardt, G. Hofmann, J. Patommel, J.-D. Grunwaldt, C. D. Damsgaard, G. Wellenreuther, G. Falkenberg, and C. G. Schroer

Appl. Phys. Lett. 102, 203104 (2013); http://dx.doi.org/10.1063/1.4807020 (4 pages)

Online Publication Date: 20 May 2013

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We combine resonant scattering with (ptychographic) scanning coherent diffraction microscopy to determine the chemical state of gold nanoparticles with high spatial resolution. Ptychographic images of the sample are recorded for a series of energies around the gold L3 absorption edge. From these data, chemical information in the form of absorption and resonant scattering spectra is reconstructed at each location in the sample. For gold nanoparticles of about 100 nm diameter, a spatial resolution of about 20–30 nm is obtained. In the future, this microscopy approach will open the way to operando studies of heterogeneous catalysts on the nanometer scale.
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81.05.Bx Metals, semimetals, and alloys
78.67.Bf Nanocrystals, nanoparticles, and nanoclusters
81.07.-b Nanoscale materials and structures: fabrication and characterization
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Photoactive self-assembled monolayers for optically switchable organic thin-film transistors

Michael Salinas and Marcus Halik

Appl. Phys. Lett. 102, 203301 (2013); http://dx.doi.org/10.1063/1.4804595 (4 pages)

Online Publication Date: 20 May 2013

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We investigate the photoconductive and photovoltaic effects in organic thin-film transistors with thin hybrid dielectrics composed of aluminum oxide and self-assembled monolayers (SAMs). By using SAM molecules with an electro-optical functionality tuning of the photoinduced charge transfer at the interface of semiconductor and SAM upon illumination with laser light can be achieved. Control of the threshold voltage by the SAM composition enables the optical operation of the transistors without applying a gate voltage and affects the dynamics of photoinduced charge transfer.
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85.30.Tv Field effect devices
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Spectral dispersion of ultrafast optical limiting in Coumarin-120 by white-light continuum Z-scan

Benoy Anand, Nivya Roy, S. Siva Sankara Sai, and Reji Philip

Appl. Phys. Lett. 102, 203302 (2013); http://dx.doi.org/10.1063/1.4807151 (5 pages)

Online Publication Date: 20 May 2013

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Measurement of the wavelength dispersion of optical limiting in materials can provide invaluable information useful for laser safety device applications. However, it can be a tedious task when conventional tunable laser sources like the optical parametric amplifier are employed for excitation. Here we report the spectral dispersion of ultrafast optical limiting in the laser dye Coumarin-120 in the wavelength region 630 to 900 nm, measured in a single Z-scan, using the white-light continuum as the excitation source. Optical limiting is found to arise from two-photon absorption, and its spectrum agrees very well in shape with the linear absorption spectrum.
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42.55.Mv Dye lasers
42.50.Md Optical transient phenomena: quantum beats, photon echo, free-induction decay, dephasings and revivals, optical nutation, and self-induced transparency
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
07.60.Rd Visible and ultraviolet spectrometers
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Laser-scanning Doppler photoacoustic microscopy based on temporal correlation

Wei Song, Wenzhong Liu, and Hao F. Zhang

Appl. Phys. Lett. 102, 203501 (2013); http://dx.doi.org/10.1063/1.4807290 (4 pages)

Online Publication Date: 20 May 2013

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We present a methodology to measure absolute flow velocity using laser-scanning photoacoustic microscopy. To obtain the Doppler angle, the angle between ultrasonic detection axis and flow direction, we extracted the distances between the transducer and three adjacent scanning points along the flow and repeatedly applied the law of cosines. To measure flow velocity along the ultrasonic detection axis, we calculated the time shift between two consecutive photoacoustic waves at the same scanning point, then converted the time shift to velocity according to the sound velocity and time interval between two laser illuminations. We verified our method by imaging flow phantoms.
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87.63.lt Laser imaging
87.64.M- Optical microscopy
87.85.Ox Biomedical instrumentation and transducers, including micro-electro-mechanical systems (MEMS)
87.57.-s Medical imaging
87.19.U- Hemodynamics

Pressure-sensing based on photothermally coupled operation of micromechanical beam resonator

D. H. Kim, E. J. Lee, M. R. Cho, C. S. Kim, Y. D. Park, and T. Kouh

Appl. Phys. Lett. 102, 203502 (2013); http://dx.doi.org/10.1063/1.4807667 (4 pages)

Online Publication Date: 20 May 2013

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Here, we demonstrate the pressure-sensing scheme based on the photothermal effect in the miniaturized beam resonator in the moderate pressure range. Since the resonance frequency of the small beam resonator under thermal stress can be easily modulated by the convective cooling of the gas molecules, the pressure change has been monitored by tracking the frequency shift under constant optical power. Our experimental measurements as well as the analytical model show that the described technique ensures the fast response to the external pressure variation with high responsivity as well as much sought-after scalability, desirable for many technological applications.
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07.20.-n Thermal instruments and apparatus
85.85.+j Micro- and nano-electromechanical systems (MEMS/NEMS) and devices
07.10.Cm Micromechanical devices and systems
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A study of oxidative stress induced by non-thermal plasma-activated water for bacterial damage

Qian Zhang, Yongdong Liang, Hongqing Feng, Ruonan Ma, Ying Tian, Jue Zhang, and Jing Fang

Appl. Phys. Lett. 102, 203701 (2013); http://dx.doi.org/10.1063/1.4807133 (4 pages)

Online Publication Date: 20 May 2013

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Ar/O2 (2%) cold plasma microjet was used to create plasma-activated water (PAW). The disinfection efficacy of PAW against Staphylococcus aureus showed that PAW can effectively disinfect bacteria. Optical emission spectra and oxidation reduction potential results demonstrated the inactivation is attributed to oxidative stress induced by reactive oxygen species in PAW. Moreover, the results of X-ray photoelectron spectroscopy, atomic absorption spectrometry, and transmission electron microscopy suggested that the chemical state of cell surface, the integrity of cell membrane, as well as the cell internal components and structure were damaged by the oxidative stress.
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87.85.-d Biomedical engineering
87.16.dt Structure, static correlations, domains, and rafts
87.16.-b Subcellular structure and processes
52.77.-j Plasma applications
87.53.-j Effects of ionizing radiation on biological systems

Thermal conductivity of single biological cells and relation with cell viability

Byoung Kyoo Park, Namwoo Yi, Jaesung Park, and Dongsik Kim

Appl. Phys. Lett. 102, 203702 (2013); http://dx.doi.org/10.1063/1.4807471 (4 pages)

Online Publication Date: 20 May 2013

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This paper presents measurements of effective thermal conductivity of single biological cells (HeLa, NIH-3T3 J2, and hepatocyte). Such cellular-level measurements have not been performed previously, due to the small size (∼10 pl) of cells. The measurement uses the three-omega method with a nanoscale thermal sensor and a micro-well structure that confines the cell. The results provide a fundamental property to investigate the thermodynamics of cells. We also measured thermal conductivity of dead cells; results were significantly different from those of live cells. The difference means that thermal conductivity can be used for probing cell viability.
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87.17.-d Cell processes
87.19.Pp Biothermics and thermal processes in biology
87.85.jc Electrical, thermal, and mechanical properties of biological matter
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Diagnosis of femtosecond plasma filament by channeling microwaves along the filament

Mostafa Alshershby, Yu Ren, Jiang Qin, Zuoqiang Hao, and Jingquan Lin

Appl. Phys. Lett. 102, 204101 (2013); http://dx.doi.org/10.1063/1.4807434 (4 pages)

Online Publication Date: 20 May 2013

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We introduce a simple, fast, and non-intrusive experimental method to obtain the basic parameters of femtosecond laser-generated plasma filament. The method is based on the channeling of microwaves along both a plasma filament and a well-defined conducting wire. By comparing the detected microwaves that propagate along the plasma filament and a copper wire with known conductivity and spatial dimension, the basic parameters of the plasma filament can be easily obtained. As a result of the possibility of channeling microwave radiation along the plasma filament, we were then able to obtain the plasma density distribution along the filament length.
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52.70.Gw Radio-frequency and microwave measurements
52.25.Fi Transport properties
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Publisher's Note: “Selective detection of tetrahedral units in amorphous GeTe-based phase change alloys using Ge L3-edge x-ray absorption near-edge structure spectroscopy” [Appl. Phys. Lett. 102, 111904 (2013)]

M. Krbal, A. V. Kolobov, P. Fons, K. V. Mitrofanov, Y. Tamenori, J. Hegedüs, S. R. Elliott, and J. Tominaga

Appl. Phys. Lett. 102, 209901 (2013); http://dx.doi.org/10.1063/1.4801918 (1 page)

Online Publication Date: 20 May 2013

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Abstract Unavailable
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99.10.Fg Publisher's note
78.70.Dm X-ray absorption spectra
81.05.Bx Metals, semimetals, and alloys
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