Browsing by Subject "Condensed matter physics"
Now showing items 1-20 of 100
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Activation behaviour and dielectric relaxation in polyvinyl alcohol and multiwall carbon nanotube composite films
(2011)The dc and ac electrical transport property of Polyvinyl Alcohol-Multiwall Carbon Nanotubes (PVA-MWNT) composites has been investigated within a temperature range 77?T?300K and in the frequency range 20Hz to 1MHz. The ... -
Ag-nanowire films coated with ZnO nanoparticles as a transparent electrode for solar cell
(2011)We demonstrate that solution-processible silver-nanowire films coated with zinc-oxide-nanoparticles (ZnO-NPs) can be used as transparent electrodes in organic photovoltaic devices. The ZnO-NP coating acts as electron ... -
Alignment instability caused by anchoring of the in-plane directors to the rubbing direction in the V-shaped switching
(2000)In order to investigate the molecular alignment in the smectic liquid crystals showing the V-shaped switching behavior, two types of the liquid crystal cells, a sandwiched cell and an open cell, were prepared. ... -
Amplitude-mode dynamics of polariton condensates
(2011)We study the stability of collective amplitude excitations in nonequilibrium polariton condensates. These excitations correspond to renormalized upper polaritons and to the collective amplitude modes of atomic gases and ... -
Anomalous magnetization reversal due to proximity effect of antiphase boundaries
(2011)Here we report anomalous double switching hysteresis loop and high coercivity (~0.1 T) in Fe3O4(110) thin films. Our analytical model based on spin chains confined within small antiphase boundary domains (APBDs) suggests ... -
Antiferroelectric and ferroelectric orderings in frustrated chiral tilted smectics and a continuous change from anticlinic SmCA* to synclinic SmC*
(2010)In a frustrated binary-mixture system of ferroelectric and antiferroelectric liquid crystals, where the border line between SmCA* and SmC* in the temperature-concentration phase diagram runs almost parallel to the ordinate ... -
Bose condensation in a model microcavity
(2000)We study the equilibrium properties of a system of dipole-active excitons coupled to a single photon mode at fixed total excitation. Treating the presence or absence of a trapped exciton as a two-level system produces a ... -
Bose condensation of cavity polaritons beyond the linear regime: The thermal equilibrium of a model microcavity
(2001)We consider a generalization of the Dicke model. This model describes localized, physically separated, saturable excitations, such as excitons bound on impurities, coupled to a single long-lived mode of an optical cavity. ... -
Characterisation of thin film silicon films deposited by plasma enhanced chemical vapour deposition at 162MHz, using a large area, scalable, multi-tile-electrode plasma source
(2011)Large area (600 ? 720 mm) depositions of hydrogenated microcrystalline silicon (?c-Si:H) have been achieved at high deposition rates using a scalable, multi-tile electrode topology. Depositions have shown local results of ... -
Chemical bonding in copper-based transparent conducting oxides: CuMO(2) (M = In, Ga, Sc)
(Institute of Physics, 2011)The geometry and electronic structure of copper-based p-type delafossite transparent conducting oxides, CuMO(2) (M = In, Ga, Sc), are studied using the generalized gradient approximation (GGA) corrected for on-site Coulomb ... -
Classical quantum crossover in magnetic stochastic resonance in uniaxial superparamagnets
(2010)It is shown that the signal-to-noise ratio of the magnetic moment fluctuations in the magnetic stochastic resonance of a quantum uniaxial paramagnet of arbitrary spin value S subjected to a weak probing ac field H(t) = ... -
Coherence properties of the microcavity polariton condensate
(2009)A theoretical model is presented which explains the dominant decoherence process in a microcavity polariton condensate. The mechanism which is invoked is the effect of self-phase modulation, whereby interactions transform ... -
Composition and strain in thin Si1-xGex virtual substrates measured by micro-Raman spectroscopy and X-ray diffraction
(2011)Micro-Raman spectroscopy was employed for the determination of the germanium content, x and strain, , in ultrathin SiGe virtual substrates grown directly on Si by molecular beam epitaxy. The growth of highly relaxed ... -
Concentration dependence of Forster resonant energy transfer between donor and acceptor nanocrystal quantum dot layers: Effect of donor-donor interactions
(2011)The influences of donor and acceptor concentrations on Forster resonant energy transfer (FRET) in a separated donor-acceptor quantum dot bilayer structure have been investigated. Donor intra-ensemble energy transfer is ... -
Controlled in situ growth of tunable plasmonic self-assembled nanoparticle arrays
(2012)Self-assembled silver nanoparticle (NP) arrays were produced by deposition at glancing angles on transparent stepped Al2O3 templates. The evolution of the plasmonic resonances has been monitored using reflection anisotropy ... -
Conventional and inverse magnetocaloric effects in La(0.45)Sr(0.55)MnO(3) nanoparticles
(2011)The magnetocaloric effect of La(0.45)Sr(0.55)MnO(3) nanoparticles was studied by dc magnetization measurements. A sample with mean particle size of about 140 nm exhibits both a conventional magnetocaloric effect around the ... -
Critical supercurrents and self organization in quantum Hall bilayers
(2010)We present a theory of interlayer tunneling in a disordered quantum Hall bilayer at total filling factor one, allowing for the effect of static vortices. In agreement with recent experiments [Phys. Rev. B 80, 165120 ... -
Current-induced energy barrier suppression for electromigration from first principles
(2011)We present an efficient method for evaluating current-induced forces in nanoscale junctions, which naturally integrates into the nonequilibrium Green's function formalism implemented within density functional theory. This ... -
Densest Columnar Structures of Hard Spheres from Sequential Deposition
(2011)The rich variety of densest columnar structures of identical hard spheres inside a cylinder can surprisingly be constructed from a simple and computationally fast sequential deposition of cylinder-touching spheres, if the ... -
Development of stiff, strong, yet tough composites by the addition of solvent exfoliated graphene to polyurethane
(2010)We have prepared graphene dispersions, stabilised by polyurethane in tetrahydrofuran and dimethylformamide. These dispersions can be drop-cast to produce free-standing composite films. The graphene mass fraction is determined ...