Enhanced kinetic stability of a bulk metallic glass by high pressure
We report the formation of a stable Pd40.16Ni9.64Cu30.12P20.08MG with bulk size underhigh pressure at room temperature. The stableMG shows remarkably enhanced thermal and kineticstability with substantially increasedglass transition temperatureTg,crystallization temperatureTx, density and mechanical properties. The uniquestability can be further reinforced byhigher pressure and maintained even aboveTg. This result can advance theglass design and the understanding of the fundamental issues inMGs. (Source: Applied Physics Letters)
Source: Applied Physics Letters - November 29, 2016 Category: Physics Authors: R. J. Xue, L. Z. Zhao, C. L. Shi, T. Ma, X. K. Xi, M. Gao, P. W. Zhu, P. Wen, X. H. Yu, C. Q. Jin, M. X. Pan, W. H. Wang and H. Y. Bai Source Type: research
Phase transitions from semiconductive amorphous to conductive polycrystalline in indium silicon oxide thin films
The enhancement in electrical conductivity and optical transparency induced by aphase transition fromamorphous topolycrystalline in lightly silicon-doped indium oxide (InSiO)thin films is studied. Thephase transition caused by simple thermal annealing transforms the InSiOthin films fromsemiconductors to conductors.Silicon atoms form SiO4 tetrahedra in InSiO, which enhances the overlap of In 5s orbitals as a result of the distortion of InO6 octahedral networks. Desorption of weakly bonded oxygen releases electrons from deep subgap states and enhances the electrical conductivity and optical transparency of thefilms. Optical ...
Source: Applied Physics Letters - November 29, 2016 Category: Physics Authors: Nobuhiko Mitoma, Bo Da, Hideki Yoshikawa, Toshihide Nabatame, Makoto Takahashi, Kazuhiro Ito, Takio Kizu, Akihiko Fujiwara and Kazuhito Tsukagoshi Source Type: research
Broadband negative refractive index obtained by plasmonic hybridization in metamaterials
We experimentally demonstrate a broadband negativerefractive index (NRI) behavior in combined dimer and fishnet dimermetamaterials operating in the GHz frequency range. The observations can be well explained by ahybridization model and are in agreement with numerical modelling results.Hybridization of the magneticresonances is obtained by reducing the distance between the layers in the dimer structures. A ratio of the double negativerefractive index bandwidth to operational frequency of approximately 10% was achieved in the fishnet dimer. The applicable frequency range of the broadband NRI was shown to scale with the size ...
Source: Applied Physics Letters - November 29, 2016 Category: Physics Authors: Hien T. Nguyen, Tung S. Bui, Sen Yan, Guy A. E. Vandenbosch, Peter Lievens, Lam D. Vu and Ewald Janssens Source Type: research
Giant third-order nonlinearity from low-loss electrochemical graphene oxide film with a high power stability
Giant third-ordernonlinearabsorption and refraction of electrochemicalgraphene oxide (EGO)film were investigated in the femtosecond regime using the single beam Z-scan technique. The excellent chemical stability of the EGOfilm under high-power illumination up to 400 mJ/cm2 is demonstrated, which can be attributed to the lowoxidation degree revealed by the optical and Raman spectroscopies. High and broadband linear transmission over 70% has been observed from the visible to the infrared range. The low-loss EGOfilm with giant third-order nonlinearity, excellent chemical stability, large-scale preparation and flexible integra...
Source: Applied Physics Letters - November 29, 2016 Category: Physics Authors: Jun Ren, Xiaorui Zheng, Zhiming Tian, Dan Li, Pu Wang and Baohua Jia Source Type: research
Surface plasmon driven lowering of the electron emission order in a carbon/gold bilayer film
We demonstrate the reduction of the nonlinear surface plasmon drivenelectron emission order from a bilayer of electron beam evaporated carbon (eC) andgold(Au). Higher confinedelectric fields, and the presence of sp2/sp3 clustering in the eC layer increase theelectron emission at lower orders via field-driven energy gain. This bilayer provides a platform for ultrafast surface plasmon driven electron sources. (Source: Applied Physics Letters)
Source: Applied Physics Letters - November 29, 2016 Category: Physics Authors: S. R. Greig, A. Morteza-Najarian, R. L. McCreery and A. Y. Elezzabi Source Type: research
Coupled-cavity-based slow light metamaterials with antireflection structures
A slow lightmetamaterial based on a coupled Fabry-P érotcavity is proposed and numerically studied usingfinite-difference time-domain simulations. The coupled cavity-based slow lightmetamaterial is composed of a periodic array of partialmirrors with low transmittance, i.e., thin metalfilms perforated with a subwavelength hole array. The tight-binding model is employed to investigate the transmission properties of the coupled-cavity-basedmetamaterial. It is shown that the group velocities of the slowly propagating modes can be controlled by adjusting the radius of holes in themirrors. We also show that undesirable reflecti...
Source: Applied Physics Letters - November 29, 2016 Category: Physics Authors: Sun-Goo Lee, Seong-Han Kim, Soo-Yong Jung, Jongjin Lee, Jong-Moon Park and Chul-Sik Kee Source Type: research
Core-shell Mie resonant structures for quantum computing applications
Quantum communications have garnered an increasing amount of interest over the last several years. One of the key components, a deterministic singlephoton source, requires both high quantum efficiency and suitable emission wavelengths, particularly for ubiquitous fiber-based systems. Solid state singlephoton sources, comprised of a crystal with isolated, optically active defects, are particularly advantageous in terms of their potential for fine control, reproducibility, ease of operation, and scalability. However, random orientation of single defects presents challenges in terms of scalable manufacturing of such sources. ...
Source: Applied Physics Letters - November 29, 2016 Category: Physics Authors: Roman Shugayev and Peter Bermel Source Type: research
An effective electrical sensing scheme using AC electrothermal flow on a biosensor platform based on a carbon nanotube network
We report a simple and efficient electrical sensing scheme that can be used to overcome the “diffusion limit” of affinity-basedbiosensors by incorporating the structural advantage of a concentricelectrodebiosensor platform and the microstirring effect ofAC electrothermal flow (ACEF). To prove the effect of ACEF on thebiosensor performance, we performed both simulations and experiments for the detection of cardiac troponin-I, which is a biomarker for acute myocardial infarction. The finite element simulation results indicate thatAC bias to theelectrode (which has a concentric structure in our device) can induce fast con...
Source: Applied Physics Letters - November 28, 2016 Category: Physics Authors: Won Cheol Lee, Hoseok Lee, Jaeheung Lim and Young June Park Source Type: research
Theoretical and experimental analysis of the photoluminescence and photoluminescence excitation spectroscopy spectra of m-plane InGaN/GaN quantum wells
We present a combined theoretical and experimental analysis of theoptical properties ofm-plane InGaN/GaNquantum wells. The sample was studied byphotoluminescence andphotoluminescence excitation spectroscopy at low temperature. Thespectra show a large Stokes shift between the lowestexciton peak in the excitationspectra and the peak of thephotoluminescencespectrum. This behavior is indicative of strong carrierlocalization effects. These experimental results are complemented by tight-binding calculations, accounting for randomalloy fluctuations and Coulomb effects. The theoretical data explain the main features of the experim...
Source: Applied Physics Letters - November 28, 2016 Category: Physics Authors: S. Schulz, D. S. P. Tanner, E. P. O'Reilly, M. A. Caro, F. Tang, J. T. Griffiths, F. Oehler, M. J. Kappers, R. A. Oliver, C. J. Humphreys, D. Sutherland, M. J. Davies and P. Dawson Source Type: research
Synthesis of large monolayer single crystal MoS2 nanosheets with uniform size through a double-tube technology
Two-dimensional MoS2 attracts much attention because of its potential application in electronic and optoelectronic devices at present. However, the preparation of large and uniformsingle crystal MoS2nanosheets is still a challenge, which restricts its further application. Herein,monolayersingle crystal MoS2nanosheets with large and uniform grain size have been synthesized bychemical vapor deposition using a double-tube system. Within the main growth area, the grain size reaches 146 μm on the substrate of SiO2/Si, and the portion of MoS2nanosheets with grain size between 50 μm and 100 μm is up to 78%. Meanwhile,...
Source: Applied Physics Letters - November 28, 2016 Category: Physics Authors: Zhiyun Tu, Gaoda Li, Xia Ni, Leixin Meng, Suo Bai, Xiaobo Chen, Junjie Lou and Yong Qin Source Type: research
Spin-orbit torques in perpendicularly magnetized Ir22Mn78/Co20Fe60B20/MgO multilayer
The current-induced spin-orbit torques (SOTs) in the perpendicularly magnetized Ir22Mn78/Co20Fe60B20/MgO structures are investigated. The damping- and field-like torques are characterized using a harmonic technique. The spin Hall angle of Ir22Mn78 is determined to beθSHE = +0.057 ± 0.002. The SOT-driven magnetization switching is also demonstrated with the assistance of an external in-plane field. Furthermore, themagneto-optical Kerr effect imaging experiments show that the magnetization switching is realized through domainnucleation anddomain wall motion. These results may promise potential practical applications ...
Source: Applied Physics Letters - November 28, 2016 Category: Physics Authors: Di Wu, Guoqiang Yu, Ching-Tzu Chen, Seyed Armin Razavi, Qiming Shao, Xiang Li, Bingcheng Zhao, Kin L. Wong, Congli He, Zongzhi Zhang, Pedram Khalili Amiri and Kang L. Wang Source Type: research
The linewidth enhancement factor of intersubband lasers: From a two-level limit to gain without inversion conditions
Thelinewidth enhancement ( α factor) due to fluctuations in therefractive index induced by carrier fluctuations of intersubband lasers was initially expected to be zero. However, values ranging from −0.5 to 3 have been found experimentally. This paper resolves this controversy showing that counter rotating terms, usually ignored in simulations, are the actual fundamental origin of nonzero α at peak gain even without the inclusion of nonparabolicity and manybody effects, which are however nee ded to explain negative values. For laser without inversion conditions, significant as a potential out of the boxsolution for the...
Source: Applied Physics Letters - November 28, 2016 Category: Physics Authors: M. F. Pereira Source Type: research
Polarization-induced electrical conductivity in ultra-wide band gap AlGaN alloys
Unintentionallydoped (UID)AlGaN epilayers graded overAl compositions of 80% –90% and 80%–100% weregrown by metal organic vapor phase epitaxy and were electrically characterized using contactless sheetresistance (Rsh) and capacitance-voltage (C –V) measurements. Strong electrical conductivity in the UID gradedAlGaN epilayers resulted from polarization-induceddoping and was verified by the lowresistivity of 0.04 Ω cm for theAlGaN epilayer graded over 80% –100%Al mole fraction. A free electron concentration (n) of 4.8 × 1017 cm−3 was measured byC –V forAl compositions of 80% –100%. Average electron mob...
Source: Applied Physics Letters - November 28, 2016 Category: Physics Authors: Andrew M. Armstrong and Andrew A. Allerman Source Type: research
Generation of shear waves by laser in soft media in the ablative and thermoelastic regimes
This article describes the generation of elastic shearwaves in a soft medium using alaser beam. Our experiments show two different regimes depending on laser energy. Physical modeling of the underlying phenomena reveals a thermoelastic regime caused by a local dilatation resulting from temperature increase and an ablative regime caused by a partialvaporization of the medium by the laser. The computed theoretical displacements are close to the experimental measurements. A numerical study based on the physical modeling gives propagation patterns comparable to those generated experimentally. These results provide a physical b...
Source: Applied Physics Letters - November 28, 2016 Category: Physics Authors: Pol Grasland-Mongrain, Yuankang Lu, Fr édéric Lesage, Stefan Catheline and Guy Cloutier Source Type: research
Generation of two types of nonclassical optical states using an optical parametric oscillator with a PPKTP crystal
As important members of nonclassical states of light,squeezed states and entangled states are basic resources for realizing quantummeasurements and constructing quantum information networks. We experimentally demonstrate that the two types of nonclassical optical states can be generated from anoptical parametric oscillator(OPO) involving a periodically poled KTiOPO4 crystal with a domain-inversion period of 51.7 μm, by changing thepolarization of the pump laser. When a vertically polarized 671 nm laser is used to pump theOPO, the intra-cavity frequency-down-conversion with type-0 quasi-phase matching is realized and...
Source: Applied Physics Letters - November 28, 2016 Category: Physics Authors: Meiru Huo, Jiliang Qin, Zhihui Yan, Xiaojun Jia and Kunchi Peng Source Type: research
