156 research outputs found
Strong modification of the reflection from birefringent layers of semiconductor nanowires by nanoshells
The propagation of light in layers of vertically aligned nanowires is determined by their unique and extreme optical properties. Depending on the nanowire filling fraction and their diameter, layers of nanowires form strongly birefringent media. This large birefringence gives rise to sharp angle dependent peaks in polarized reflection. We demonstrate experimentally the tunability of the reflection by adding shells of SiO2 with thicknesses ranging from 10Âżnm to 30Âżnm around the nanowires. The strong modification of the reflection peaks renders nanowire layers as a promising candidate for sensing applications
Optical transmission matrix as a probe of the photonic interaction strength
We demonstrate that optical transmission matrices (TM) of disordered complex media provide a powerful tool to extract the photonic interaction strength, independent of surface effects. We measure TM of strongly scattering GaP nanowires and plot the singular value density of the measured matrices and a random matrix model. By varying the free parameters of the model, the transport mean free path and effective refractive index, we retrieve the photonic interaction strength. From numerical simulations we conclude that TM statistics is hardly sensitive to surface effects, in contrast to enhanced backscattering or total transmission based methods
Surround-gated vertical nanowire quantum dots
We report voltage dependent photoluminescence experiments on single indium arsenide phosphide (InAsP) quantum dots embedded in vertical surround-gated indium phosphide (InP) nanowires. We show that by tuning the gate voltage, we can access different quantum dot charge states. We study the anisotropic exchange splitting by polarization analysis, and identify the neutral and singly charged exciton. These results are important for spin addressability in a charge tunable nanowire quantum dot
Grand Challenges of Evolutionary Psychology
In this paper we present our recent developments in control and manipulation of individual spins and photons in a single nanowire quantum dot. Specific examples include demonstration of optical excitation of single spin states, charge tunable quantum devices and single photon sources. We will also discuss our recent discovery of a new type of charge confinement - crystal phase quantum dots. They are formed from the same material with different crystal structure, and today can only be realized in nanowires
Electric Device with Nanowires Comprising a Phase Change Material
The method according to the invention is directed to manufacturing an electric device ( 100 ) according to the invention, having a body ( 102 ) with a resistor comprising a phase change material being changeable between a first phase and a second phase, the resistor having a first electrical resistance when the phase change material is in the first phase, and a second electrical resistance different from the first electrical resistance when the phase change material is in the second phase. The resistor is a nanowire (NW) electrically connecting a first conductor ( 172, 120 ) and a second conductor ( 108, 121 ).; The method comprises the step of providing a body ( 102 ) having the first conductor ( 172, 120 ), providing the first conductor ( 172, 120 ) with the nanowire (NW) thereby electrically connecting the nanowire (NW) and the first conductor ( 172, 120 ), and providing the nanowire (NW) with the second conductor ( 108, 121 ) thereby electrically connecting the nanowire (NW) and the second conductor ( 108, 121 )
Optical information recording medium
The invention relates to an optical information recording medium and methods and devices to record and read information thereto and thereof. The optical information recording medium comprises luminescent nano-elements. The nano-element species differ in at least one luminescence wavelength. Therefore, a specific luminescence signal is obtained in accordance with the nano-element species irradited by a reading light beam. Methods and devices to record and read information by using such optical information recording media are also described
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