Open Access. Powered by Scholars. Published by Universities.^{®}
 Keyword

 Selected recent publications (9)
 Nanotechnology (6)
 Metamaterials (6)
 Gold (6)
 Plasmonics (5)

 Nanowires (5)
 Nanocomposites (5)
 Refractive index (5)
 Silver (4)
 Ferromagnetism (4)
 Plasmons (3)
 Aluminium compounds (3)
 Zirconium nitride (3)
 Titanium nitride (3)
 Presentations (3)
 Visible spectra (3)
 Ultraviolet spectra (3)
 Carbon nanotubes (CNTs) (3)
 Optical materials (3)
 Infrared spectra (3)
 Refractory plasmonics (3)
 Doping (3)
 Hydrogen (3)
 Dielectric materials (3)
 Dewetting (2)
 Electrical Engineering (2)
 Electron gas (2)
 Downconversion (2)
 Alumina (2)
 Electron mobility (2)
 Publication Year
 Publication
 File Type
Articles 31  54 of 54
FullText Articles in Physics
Binary Nanoparticle Dispersed Metamaterial Implementation And Characterization, Han Li
Binary Nanoparticle Dispersed Metamaterial Implementation And Characterization, Han Li
Han Li
No abstract provided.
Controlling Nanoparticles Formation In Molten Metallic Bilayers By PulsedLaser Interference Heating, Mikhail Khenner, Sagar Yadavali, Ramki Kalyanaraman
Controlling Nanoparticles Formation In Molten Metallic Bilayers By PulsedLaser Interference Heating, Mikhail Khenner, Sagar Yadavali, Ramki Kalyanaraman
Mikhail Khenner
The impacts of the twobeam interference heating on the number of coreshell and embedded nanoparticles and on nanostructure coarsening are studied numerically based on the nonlinear dynamical model for dewetting of the pulsedlaser irradiated, thin (< 20 nm) metallic bilayers. The model incorporates thermocapillary forces and disjoining pressures, and assumes dewetting from the optically transparent substrate atop of the reflective support layer, which results in the complicated dependence of light reflectivity and absorption on the thicknesses of the layers. Stabilizing thermocapillary effect is due to the local thicknessdependent, steady state temperature profile in the liquid, which is derived based on the mean substrate temperature estimated from the elaborate thermal model of transient heating and melting/freezing. Linear stability analysis of the model equations set for Ag/Co bilayer predicts the dewetting length scales in the qualitative agreement with experiment.
Formation Of Organized Nanostructures From Unstable Bilayers Of Thin Metallic Liquids, Mikhail Khenner, Sagar Yadavali, Ramki Kalyanaraman
Formation Of Organized Nanostructures From Unstable Bilayers Of Thin Metallic Liquids, Mikhail Khenner, Sagar Yadavali, Ramki Kalyanaraman
Mikhail Khenner
Dewetting of pulsedlaser irradiated, thin (< 20 nm), optically reflective metallic bilayers on an optically transparent substrate with a reflective support layer is studied within the lubrication equations model. A steadystate bilayer film thickness (h) dependent temperature profile is derived based on the mean substrate temperature estimated from the elaborate thermal model of transient heating and melting/freezing. Large thermocapillary forces are observed along the plane of the liquidliquid and liquidgas interfaces due to this hdependent temperature, which, in turn, is strongly influenced by the hdependent laser light reflection and absorption. Consequently the dewetting is a result of the competition between thermocapillary and intermolecular forces. A linear analysis of the dewetting length scales established that the nonisothermal calculations better predict the experimental results as compared to the isothermal case within the bounding Hamaker coefficients. Subsequently, a computational nonlinear dynamics study of the dewetting pathway was performed for Ag/Co and Co/Ag bilayer systems to predict the morphology evolution. We found that the systems evolve towards formation of different morphologies, including coreshell, embedded, or stacked nanostructure morphologies.
Investigation Of Electrical Transport In Hydrogenated Multiwalled Carbon Nanotubes, Adam Friedman, Hyunkyung Chun, Don Heiman, Yung Jung, Latika Menon
Investigation Of Electrical Transport In Hydrogenated Multiwalled Carbon Nanotubes, Adam Friedman, Hyunkyung Chun, Don Heiman, Yung Jung, Latika Menon
Latika Menon
Highly disordered multiwalled carbon nanotubes of large outer diameter (~60 nm) fabricated by means of chemical vapor deposition process inside porous alumina templates exhibit ferromagnetism when annealed in a H2/Ar atmosphere. In the presence of an applied magnetic field, there is a transition from positive to negative magnetoresistance. The transition may be explained in terms of the Bright model for ordered and disordered carbon structures. Additionally, temperature dependent electrical transport experiments exhibit a zerobias anomaly at low temperature.
Nanoengineering Of A NegativeIndex BinaryStaircase Lens For The Optics Regime, Bernard Didier F. Casse, Ravinder K. Banyal, W. T. Lu, Y. J. Huang, Selvapraba Selvarasah, Mehmet R. Dokmeci, Srinivas Sridhar
Nanoengineering Of A NegativeIndex BinaryStaircase Lens For The Optics Regime, Bernard Didier F. Casse, Ravinder K. Banyal, W. T. Lu, Y. J. Huang, Selvapraba Selvarasah, Mehmet R. Dokmeci, Srinivas Sridhar
Mehmet R. Dokmeci
We show that a binarystaircase optical element can be engineered to exhibit an effective negative index of refraction, thereby expanding the range of optical properties theoretically available for future optoelectronic devices. The mechanism for achieving a negativeindex lens is based on exploiting the periodicity of the surface corrugation. By designing and nanofabricating a planoconcave binarystaircase lens in the InP/InGaAsP platform, we have experimentally demonstrated at 1.55 μm that such negativeindex concave lenses can focus plane waves. The beam propagation in the lens was studied experimentally and was in excellent agreement with the threedimensional finitedifference timedomain numerical simulations.
Nanoengineering Of A NegativeIndex BinaryStaircase Lens For The Optics Regime, Bernard Didier Casse, Ravinder Banyal, W. Lu, Y. Huang, Selvapraba Selvarasah, Mehmet Dokmeci, Srinivas Sridhar
Nanoengineering Of A NegativeIndex BinaryStaircase Lens For The Optics Regime, Bernard Didier Casse, Ravinder Banyal, W. Lu, Y. Huang, Selvapraba Selvarasah, Mehmet Dokmeci, Srinivas Sridhar
Srinivas Sridhar
We show that a binarystaircase optical element can be engineered to exhibit an effective negative index of refraction, thereby expanding the range of optical properties theoretically available for future optoelectronic devices. The mechanism for achieving a negativeindex lens is based on exploiting the periodicity of the surface corrugation. By designing and nanofabricating a planoconcave binarystaircase lens in the InP/InGaAsP platform, we have experimentally demonstrated at 1.55 μm that such negativeindex concave lenses can focus plane waves. The beam propagation in the lens was studied experimentally and was in excellent agreement with the threedimensional finitedifference timedomain numerical simulations.
Microwave Absorption Of Patterned Arrays Of Nanosized Magnetic Stripes With Different Aspect Ratios, Leszek M. Malkinski, Minghui Yu, Andriy Y. Voyk, Donald J. Scherer Ii, Leonard Spinu, Weillie Zhou, Scott Whittenburg, Zachary Davis, JinSeung Jung
Microwave Absorption Of Patterned Arrays Of Nanosized Magnetic Stripes With Different Aspect Ratios, Leszek M. Malkinski, Minghui Yu, Andriy Y. Voyk, Donald J. Scherer Ii, Leonard Spinu, Weillie Zhou, Scott Whittenburg, Zachary Davis, JinSeung Jung
Scott L Whittenburg
Arrays consisting of nanosized stripes of Permalloy with different lengthtowidth ratios have been fabricated using electron beam nanolithography, magnetron sputtering, and liftoff process. These stripes have a thickness of 100 nm, a width of 300 nm, and different lengths ranging from 300 nm to 100 μm. The stripes are separated by a distance of 1 μm. Magnetization hysteresis loops were measured using a superconducting quantum interference device susceptometer. Microwave absorption at 9.8 GHz was determined by means of ferromagnetic resonance technique. The dependence of the resonant field on the angle between the nanostructure and the inplane dc magnetic field ...
Stability Of A Strongly Anisotropic Thin Epitaxial Film In A Wetting Interaction With Elastic Substrate, Mikhail Khenner, Wondimu T. Tekalign, Margo S. Levine
Stability Of A Strongly Anisotropic Thin Epitaxial Film In A Wetting Interaction With Elastic Substrate, Mikhail Khenner, Wondimu T. Tekalign, Margo S. Levine
Mikhail Khenner
The linear dispersion relation for longwave surface perturbations, as derived by Levine et al. Phys. Rev. B 75, 205312 (2007) is extended to include a smooth surface energy anisotropy function with a variable anisotropy strength (from weak to strong, such that sharp corners and slightly curved facets occur on the corresponding Wulff shape). Through detailed parametric studies it is shown that a combination of a wetting interaction and strong anisotropy, and even a wetting interaction alone results in complicated linear stability characteristics of strained and unstrained films.
Modeling Diverse Physics Of Nanoparticle SelfAssembly In Pulsed LaserIrradiated Metallic Films, Mikhail Khenner
Modeling Diverse Physics Of Nanoparticle SelfAssembly In Pulsed LaserIrradiated Metallic Films, Mikhail Khenner
Mikhail Khenner
Presents physics behind dewetting of thin liquid films and mathematical/computational modeling tools (Educational/Research presentation for senior physics majors).
Effect Of Particle Properties And Light Polarization On The Plasmonic Resonances In Metallic Nanoparticles, U. Guler, R. Turan
Effect Of Particle Properties And Light Polarization On The Plasmonic Resonances In Metallic Nanoparticles, U. Guler, R. Turan
U. Guler
The resonance behavior of localized surface plasmons in silver and gold nanoparticles was studied in the visible and nearinfrared regions of the electromagnetic spectrum. Arrays of nanosized gold (Au) and silver (Ag) particles with different properties were produced with electronbeam lithography technique over glass substrates. The effect of the particle size, shape variations, period, thickness, metal type, substrate type and sulfidation were studied via transmission and reflectance measurements. The results are compared with the theoretical calculations based on the DDA simulations performed by software developed in this study. We propose a new intensity modulation technique based on localized surface plasmons ...
Morphological Evolution Of SingleCrystal Ultrathin Solid Films, Mikhail Khenner
Morphological Evolution Of SingleCrystal Ultrathin Solid Films, Mikhail Khenner
Mikhail Khenner
An introduction to mathematical modeling of ultrathin solid films and the role of such modeling in nanotechnologies: Educational/Research presentation for senior physics majors
A TangentPlane, MarkerParticle Method For The Computation Of ThreeDimensional Solid Surfaces Evolving By Surface Diffusion On A Substrate, Ping Du, Mikhail Khenner, Harris Wong
A TangentPlane, MarkerParticle Method For The Computation Of ThreeDimensional Solid Surfaces Evolving By Surface Diffusion On A Substrate, Ping Du, Mikhail Khenner, Harris Wong
Mikhail Khenner
We introduce a markerparticle method for the computation of threedimensional solid surface morphologies evolving by surface diffusion. The method does not use gridding of surfaces or numerical differentiation, and applies to surfaces with finite slopes and overhangs. We demonstrate the method by computing the evolution of perturbed cylindrical wires on a substrate. We show that computed growth rates at early times agree with those predicted by the linear stability analysis. Furthermore, when the marker particles are redistributed periodically to maintain even spacing, the method can follow breakup of the wire.
Oscillatory And Monotonic Modes Of LongWave Marangoni Convection In A Thin Film, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev
Oscillatory And Monotonic Modes Of LongWave Marangoni Convection In A Thin Film, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev
Mikhail Khenner
We study longwave Marangoni convection in a layer heated from below. Using the scaling k=O#1;#3;Bi#2;, where k is the wave number and Bi is the Biot number, we derive a set of amplitude equations. Analysis of this set shows presence of monotonic and oscillatory modes of instability. Oscillatory mode has not been previously found for such direction of heating. Studies of weakly nonlinear dynamics demonstrate that stable steady and oscillatory patterns can be found near the stability threshold.
ThicknessDependent Spontaneous Dewetting Morphology Of Ultrathin Ag Films, H Krishna, R Sachan, J Strader, C Favazza, Mikhail Khenner, Ramki Kalyanaraman
ThicknessDependent Spontaneous Dewetting Morphology Of Ultrathin Ag Films, H Krishna, R Sachan, J Strader, C Favazza, Mikhail Khenner, Ramki Kalyanaraman
Mikhail Khenner
We show here that the morphological pathway of spontaneous dewetting of ultrathin Ag films on SiO2 under nanosecond laser melting is found to be film thickness dependent. For films with thickness h between 2<=h<=9.5 nm, the intermediate stages of the morphology consisted of bicontinuous structures. For films 11.5<=h<=20 nm, the intermediate stages consisted of regularlysized holes. Measurement of the characteristic length scales for different stages of dewetting as a function of film thickness showed a systematic increase, which is consistent with the spinodal dewetting instability over the entire thickness range investigated. This change in morphology with thickness is consistent with observations made previously for polymer films [A. Shama et al, Phys. Rev. Lett., v81, pp3463 (1998); R. Seemann et al, J. Phys. Cond. Matt., v13, pp4925, (2001)]. Based on the behavior of free energy curvature that incorporates intermolecular forces, we have estimated the morphological transition thickness for Ag on SiO2. The theory predictions agree well with observations for Ag. These results show that it is possible to form a variety of complex Ag nanomorphologies in a consistent manner, which could be useful in optical applications of Ag surfaces, such as in surface enhanced Raman sensing.
Thermocapillary Effects In Driven Dewetting And SelfAssembly Of Pulsed LaserIrradiated Metallic Films, Mikhail Khenner
Thermocapillary Effects In Driven Dewetting And SelfAssembly Of Pulsed LaserIrradiated Metallic Films, Mikhail Khenner
Mikhail Khenner
A mathematical model for the evolution of pulsed laserirradiated, molten metallic films has been developed using the lubrication theory. The heat transfer problem that incorporates the absorbed heat from a single laser beam or the interfering laser beams is solved analytically. Using this temperature field, we derive the 3D longwave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the reflectivity, the peak laser beam ...
Thermocapillary Effects In Driven Dewetting And SelfAssembly Of Pulsed LaserIrradiated Metallic Films, Agegnehu Atena, Mikhail Khenner
Thermocapillary Effects In Driven Dewetting And SelfAssembly Of Pulsed LaserIrradiated Metallic Films, Agegnehu Atena, Mikhail Khenner
Mikhail Khenner
In this paper the lubricationtype dynamical model is developed of a molten, pulsed laserirradiated metallic film. The heat transfer problem that incorporates the absorbed heat from a single beam or interfering beams is solved analytically. Using this temperature field, we derive the 3D longwave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the peak laser beam intensity, the film optical thickness, the Biot and ...
Quantum Transport In In_{0.75}Ga_{0.25}As Quantum Wires, P. J. Simmonds, F. Sfigakis, H. E. Beere, D. A. Ritchie, M. Pepper, D. Anderson, G. A.C. Jones
Quantum Transport In In0.75Ga0.25As Quantum Wires, P. J. Simmonds, F. Sfigakis, H. E. Beere, D. A. Ritchie, M. Pepper, D. Anderson, G. A.C. Jones
Paul J. Simmonds
In addition to quantized conductance plateaus at integer multiples of 2e^{2}/h, the differential conductance G=dI/dV shows plateaus at 0.25(2e^{2}/h) and 0.75(2e^{2}/h) under applied sourcedrain bias in In_{0.75}Ga_{0.25}As quantum wires defined by insulated split gates. This observation is consistent with a spingap model for the 0.7 structure. Using a tilted magnetic field to induce Landau level crossings, the g factor was measured to be ~9 by the coincidence method. This material, with a mobility of 1.8×10^{5 ...}
Morphologies And Kinetics Of A Dewetting Ultrathin Solid Film, Mikhail Khenner
Morphologies And Kinetics Of A Dewetting Ultrathin Solid Film, Mikhail Khenner
Mikhail Khenner
The surface evolution model based on geometric partial differential equation is used to numerically study the kinetics of dewetting and dynamic morphologies for the localized pinhole defect in the surface of the ultrathin solid film with the strongly anisotropic surface energy. Depending on parameters such as the initial depth and width of the pinole, the strength of the attractive substrate potential and the strength of the surface energy anisotropy, the pinhole may either extend to the substrate and thus rupture the film, or evolve to the quasiequilibrium shape while the rest of the film surface undergoes phase separation into a ...
Enhanced Stability Of A Dewetting Thin Liquid Film In A SingleFrequency Vibration Field, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev
Enhanced Stability Of A Dewetting Thin Liquid Film In A SingleFrequency Vibration Field, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev
Mikhail Khenner
Dynamics of a thin dewetting liquid film on a vertically oscillating substrate is considered. We assume moderate vibration frequency and large (compared to the mean film thickness) vibration amplitude. Using the lubrication approximation and the averaging method, we formulate the coupled sets of equations governing the pulsatile and the averaged fluid flows in the film, and then derive the nonlinear amplitude equation for the averaged film thickness. We show that there exists a window in the frequencyamplitude domain where the parametric and shearflow instabilities of the pulsatile flow do not emerge. As a consequence, in this window the averaged description ...
GrowthTemperature Optimization For Low CarrierDensity In_{0.75}Ga_{0.25}AsBased High Electron Mobility Transistors On Inp, Paul J. Simmonds, H. E. Beere, D. A. Ritchie, S. N. Holmes
GrowthTemperature Optimization For Low CarrierDensity In0.75Ga0.25AsBased High Electron Mobility Transistors On Inp, Paul J. Simmonds, H. E. Beere, D. A. Ritchie, S. N. Holmes
Paul J. Simmonds
Twodimensional electron gases (2DEGs) were formed in undoped In_{0.75}Al_{0.25}As / In_{0.75}Ga_{0.25}As / In_{0.75}Al_{0.25}As quantum wells. The optimal growth temperature for this structure is 410°C, with peak 2DEG electron mobility and density values of μ = 221000 cm^{2}/V s and n = 1.36 × 10^{11} cm^{−2} at 1.5 K. This electron mobility is equal to the highest previously published for these undoped structures but with a factor of 2 reduction in n. This has been achieved through the use of a ...
Quantum Dot Resonant Tunneling Diodes For Telecom Wavelength Single Photon Detection, H. W. Li, Paul J. Simmonds, H. E. Beere, B. E. Kardynał, D. A. Ritchie, A. J. Shields
Quantum Dot Resonant Tunneling Diodes For Telecom Wavelength Single Photon Detection, H. W. Li, Paul J. Simmonds, H. E. Beere, B. E. Kardynał, D. A. Ritchie, A. J. Shields
Paul J. Simmonds
Single photon detection was realized at a telecom wavelength with quantum dot resonant tunneling diodes grown on an InP substrate. The structure contains a AlAs/In_{0.53}Ga_{0.47}As/AlAs quantum well with InAs quantum dots grown on the top AlAs barrier. The single photon detection efficiency of the device under 1310 nm illumination was measured to be about 0.35% ± 0.07% with a dark count rate of 1.58×10^{6} ns^{1}. This corresponds to an internal efficiency of 6.3%.
Quantum Dot Resonant Tunneling Diode For Telecommunication Wavelength Single Photon Detection, H. W. Li, B. E. Kardynał, P. See, A. J. Shields, P. Simmonds, H. E. Beere, D. A. Ritchie
Quantum Dot Resonant Tunneling Diode For Telecommunication Wavelength Single Photon Detection, H. W. Li, B. E. Kardynał, P. See, A. J. Shields, P. Simmonds, H. E. Beere, D. A. Ritchie
Paul J. Simmonds
The authors present a quantum dot (QD) based single photon detector operating at a fiber optic telecommunication wavelength. The detector is based on an AlAs/In_{0.53}Ga_{0.47}As/AlAs doublebarrier resonant tunneling diode containing a layer of selfassembled InAs QDs grown on an InP substrate. The device shows an internal efficiency of about 6.3% with a dark count rate of 1.58 × 10^{−6} ns^{−1} for 1310 nm photons.
Growth By Molecular Beam Epitaxy Of SelfAssembled Inas Quantum Dots On Inalas And Ingaas LatticeMatched To Inp, Paul J. Simmonds, H W. Li, H E. Beere, P See, A J. Shields, D A. Ritchie
Growth By Molecular Beam Epitaxy Of SelfAssembled Inas Quantum Dots On Inalas And Ingaas LatticeMatched To Inp, Paul J. Simmonds, H W. Li, H E. Beere, P See, A J. Shields, D A. Ritchie
Paul J. Simmonds
The authors report the results of a detailed study of the effect of growth conditions, for molecular beam epitaxy, on the structural and optical properties of selfassembled InAs quantum dots (QDs) on In_{0.524}Al_{0.476}As. InAs QDs both buried in, and on top of, In_{0.524}Al_{0.476}As were analyzed using photoluminescence (PL) and atomic force microscopy. InAs QD morphology and peak PL emission wavelength both scale linearly with deposition thickness in monolayers (MLs). InAs deposition thickness can be used to tune QD PL wavelength by 170 nm/ML, over a range of ...
Science And Engineering Of NanoparticlePolymer Composites: Insights From Computer Simulation, Francis W. Starr, Sharon C. Glotzer
Science And Engineering Of NanoparticlePolymer Composites: Insights From Computer Simulation, Francis W. Starr, Sharon C. Glotzer
Francis Starr
No abstract provided.