741 research outputs found
A high performance surface acoustic wave visible light sensor using novel materials: Bi2S3 nanobelts
Low dimensional Bi2S3 materials are excellent for use in photodetectors with excellent stability and fast response time. In this work, we developed a visible light sensor with good performance based on surface acoustic wave (SAW) devices using Bi2S3 nanobelts as the sensing materials. The SAW delay-line sensor was fabricated on ST-cut quartz with a designed wavelength of 15.8 microns using conventional photolithography techniques. The measured center frequency was 200.02 MHz. The Bi2S3 nanobelts prepared by a facile hydrothermal process were deposited onto SAW sensors by spin-coating. Under irradiation of 625 nm visible light with a power intensity of 170 μW cm−2, the sensor showed a fast and large response with a frequency upshift of 7 kHz within 1 s. The upshift of the frequency of the SAW device is mainly attributed to the mass loading effect caused by the desorption of oxygen from the Bi2S3 nanobelts under visible light radiation
A high performance surface acoustic wave visible light sensor using novel materials: Bi2S3 nanobelts
Low dimensional Bi2S3 materials are excellent for use in photodetectors with excellent stability and fast response time. In this work, we developed a visible light sensor with good performance based on surface acoustic wave (SAW) devices using Bi2S3 nanobelts as the sensing materials. The SAW delay-line sensor was fabricated on ST-cut quartz with a designed wavelength of 15.8 microns using conventional photolithography techniques. The measured center frequency was 200.02 MHz. The Bi2S3 nanobelts prepared by a facile hydrothermal process were deposited onto SAW sensors by spin-coating. Under irradiation of 625 nm visible light with a power intensity of 170 μW cm−2, the sensor showed a fast and large response with a frequency upshift of 7 kHz within 1 s. The upshift of the frequency of the SAW device is mainly attributed to the mass loading effect caused by the desorption of oxygen from the Bi2S3 nanobelts under visible light radiation
Entanglement Structure: Entanglement Partitioning in Multipartite Systems and Its Experimental Detection Using Optimizable Witnesses
Creating large-scale entanglement lies at the heart of many quantum
information processing protocols and the investigation of fundamental physics.
For multipartite quantum systems, it is crucial to identify not only the
presence of entanglement but also its detailed structure. This is because in a
generic experimental situation with sufficiently many subsystems involved, the
production of so-called genuine multipartite entanglement remains a formidable
challenge. Consequently, focusing exclusively on the identification of this
strongest type of entanglement may result in an all or nothing situation where
some inherently quantum aspects of the resource are overlooked. On the
contrary, even if the system is not genuinely multipartite entangled, there may
still be many-body entanglement present in the system. An identification of the
entanglement structure may thus provide us with a hint about where
imperfections in the setup may occur, as well as where we can identify groups
of subsystems that can still exhibit strong quantum-information-processing
capabilities. However, there is no known efficient methods to identify the
underlying entanglement structure. Here, we propose two complementary families
of witnesses for the identification of such structures. They are based on the
detection of entanglement intactness and entanglement depth, each requires only
the implementation of solely two local measurements. Our method is also robust
against noises and other imperfections, as reflected by our experimental
implementation of these tools to verify the entanglement structure of five
different eight-photon entangled states. We demonstrate how their entanglement
structure can be precisely and systematically inferred from the experimental
data. In achieving this goal, we also illustrate how the same set of data can
be classically postprocessed to learn the most about the measured system.Comment: 21 pages, 13 figure
A novel quartz-crystal microbalance humidity sensor based on solution-processible indium oxide quantum dots
Large surface area, like quantum confinement effect also caused by particular nano level size of quantum dots (QDs), brings fantastic possibility for humidity sensing. High concentration of surface adsorption site initiate response increasing. Porosity between QDs stacking up fast water vapor penetration and flowing away. Here, a quartz-crystal microbalance (QCM) humidity sensor was prepared using the indium oxide (In2O3) QDs, synthesized via solvothermal method. After In2O3 QDs directly spin-coating onto the QCM, an annealing process taken place to remove organic long chains and expose more moisture adsorption sites on the surface of the QDs. The annealed QCM humidity sensor exhibited high sensitivity (56.3 Hz/%RH at 86.3% RH), with a fast response/recovery time (14 s/16 s). Long carbon chains break down and hydrogen-bonded hydroxyl groups chemisorpted to the QDs. Chemical reaction was reduced by these chemisorpted hydrogen-bonded hydroxyl groups. Mass changing was mostly caused by fast multilayer physiorption. So the transducer can effectively and precisely monitor the moisture of person’s breathing. In2O3 QDs modified QCM sensors demonstrating its promising humidity sensing applications in daily life
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