Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title> <jats:p>In this study, we propose a novel junction terminal extension structure for vertical diamond Schottky barrier diode by using the n-Ga<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>/p-diamond heterojunction. The depletion region of the heterojunction suppresses part of the forward current conduction path, which increases the on-resistance slightly. On the other hand, the reverse breakdown voltage is enhanced obviously because of the attenuated electric field crowding. By optimizing the doping concentration, length, and depth of the n-type Ga<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>, trade-off between on-resistance and breakdown voltage with a high Baliga's FOM value is realized through Silvaco TCAD simulation. In addition, the effect of the work function of Schottky electrode is also evaluated. Those results are beneficial to realize a high-performance vertical diamond SBD.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>In this study, the relationship between spatial position of diamond seed and growth mode has been investigated with an enclosed-type holder for single-crystal diamond growth using MPCVD epitaxial method. It demonstrates that there are mainly three different regions by varying the spatial position of seed. Owing to the plasma concentration occurs at seed edge, a relatively deeper depth is beneficial to transfer the plasma to the holder surface and suppress the polycrystalline diamond rim around the seed edge. However, the plasma density at the edge will be decreased drastically when the depth is too large, resulting in the growth of vicinal grain plane and the reduction of surface area. By adopting an appropriate spatial location, the size of a single-crystal diamond can be enlarged from 7×7×0.35 mm<jats:sup>3</jats:sup> to 8.6×8.6×2.8 mm<jats:sup>3</jats:sup> without the polycrystalline diamond rim.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We propose a new full color ghost imaging scheme by using both time and code division multiplexing technologies. In the scheme, the speckle patterns of three colors (red, green and blue) are modulated with different time slots and codes. The light intensity is sampled by one bucket detector. Then based on the modulated time slots and codes, we can effectively and simultaneously extract three detection component signals corresponding to three color components of objects from the sampling signal of the bucket detector. Finally, three component images resulting from three component detection signals can be synthesized into a full color image. The experimental results verify the feasibility of our scheme under the limit of the number of time slots and codes. Moreover, our scheme reduces the number of bucket detectors and can realize high quality imaging even in a noisy environment.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The reactive collisions of nitrogen ion with hydrogen and its isotopic variations have great significance in the field of astrophysics. Herein, the state-to-state quantum time-dependent wave packet calculations of N<jats:sup>+</jats:sup>(<jats:sup>3</jats:sup>P) + HD → NH<jats:sup>+</jats:sup>/ND<jats:sup>+</jats:sup> + D/H reaction are carried out based on the recently developed potential energy surface [Phys. Chem. Chem. Phys., 2019, 21, 22203]. The integral cross sections (ICSs) and rate coefficients of both channels are precisely determined at the state-to-state level. The results of total ICSs and rate coefficients present a dramatic preference on the ND<jats:sup>+</jats:sup> product over the NH<jats:sup>+</jats:sup> product, conforming to the long-lived complex-forming mechanism. Product state-resolved ICSs indicate that both the product molecules are difficult to excite to higher vibrational states, and the ND<jats:sup>+</jats:sup> product has a hotter rotational state distribution. Moreover, the integral cross sections and rate coefficients are precisely determined at the state-to-state level and insights are provided about the differences between the two channels. The present results would provide an important reference for the further experimental studies at the finer level for this interstellar chemical reaction. The datasets presented in this paper, including the ICSs and rate coefficients of the two products for the title reaction, are openly available at https://www.doi.org/10.57760/sciencedb.j00113.00034 (https://www.scidb.cn/s/rEju22).</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Atomic magnetometers operated in the spin-exchange relaxation-free (SERF) regime are the promising sensor to replace superconducting quantum interference devices (SQUIDs) in the biomagnetism field. The SERF magnetometer with compact size and good performance is crucial to the new generation of wearable magnetoencephalography (MEG) system. In this paper, we developed a compact and closed-loop SERF magnetometer with the dimensions of 15.0 × 22.0 × 30.0 mm<jats:sup>3</jats:sup> based on a single-beam configuration. The bandwidth of the magnetometer was extended to 675 Hz while the sensitivity was maintained at 22 fT/Hz<jats:sup>1/2</jats:sup>. A nearly 3- fold enhancement of the bandwidth was obtained in comparison with the open-loop control. The implementation of closed-loop control also greatly improved the dynamic range, enabling the magnetometer to be robust against the disturbance of the ambient field. Moreover, the magnetometer was successfully applied for the detection of human <jats:italic>α</jats:italic>-rhythm and auditory evoked fields (AEFs), which demonstrated the potential to be extended to multi-channel MEG measurements for future neuroscience studies.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Current superconducting memory devices lack the basic quality of high memory density for practical memories, primarily due to the size limitations of superconducting quantum interference devices. Here, we propose a superconductor-ferromagnet bilayer device with strain-pulse-assisted multi-bit ladder-type memory, by using strain-engineered ferromagnet domain structure to control carrier concentration in the superconductor, which is simulated by coupled Landau-Lifshitz-Gilbert and Ginzburg-Landau equations. Current- and strain-pulses were observed to deterministically control the resistivity of superconductor for one and two-bit device arrangements. The average carrier concentration of superconductor was observed to have multiple metastable states, with controllable switching using current- and strain-pulses, determining multiple resistivity states. These findings confirm the eligibility of superconductor-ferromagnet bilayers to be used as ladder-type multibit memories and open a new arena for further theoretical and experimental investigations in the direction of cryogenic memories.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Cladding fiber surface plasmon resonance (SPR) sensor has few structures, and clad SPR sensor based on S-type fiber was proposed in this paper. A new type of fiber cladding SPR sensor was formed by electrofusing an S-shaped structure on the fiber to couple the light in the fiber core to the cladding. In this paper, the effects of fiber parameters on the performance of the sensor were studied by simulation and experiment. Based on the conclusion that the smaller the core diameter is, the closer the working band of SPR resonance is to the long wavelength, and the geometric characteristics that the multimode fiber can receive the fiber cladding light of the small core diameter less mode fiber, a dual channel SPR sensor with double S-type fiber cascade was proposed. In the refractive index detection range of 1.333-1.385RIU, the resonance working band of channelⅠ is 627.66nm-759.78nm, with an average sensitivity of 2540.77nm/RIU, and the resonant working band of channelⅡ is 518.24nm - 658.2nm, with an average sensitivity of 2691.54nm/RIU. The processing method of S-type fiber cladding SPR sensor is simple, which effectively solves the problems of less cladding SPR sensor structure and difficult realization of dual channel. It is expected to be used in the fields of medical treatment and biological analysis.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>In our previous papers, the classical Fractional Fourier transform theory was incorporated into the quantum theoretical system by using the theoretical method of quantum optics, and the calculation brought about quantum mechanical operators corresponding to the generation of Fractional Fourier transform. The core function of the coordinate-momentum exchange operators in the addition law of Fractional Fourier transform was analyzed too. In this paper, the bivariate operator Hermite polynomial theory and the technique of integration within an ordered product of operators are used to establish the entanglement Fractional Fourier transform theory to the extent of quantum. New generating function formula and an operator for generating quantum entangled Fractional Fourier transform are obtained using the Fractional Fourier transform relationship in a pair of conjugated entangled state representations.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>HT-6M tokamak is restarted for Thailand Institute of Nuclear Technology, TINT. In order to ensure the smooth breakdown of plasma and obtain plasma discharge parameters, the optimization of poloidal field coils and upgrade of magnetic diagnostics are described in this article. A perfect null field (the stray field in main chamber &amp;#60; 10<jats:italic>G</jats:italic>) is obtained using ohmic heating field. To get the main information of plasma, an external magnetic diagnostics system is designed and calibrated, including Rogowski coil (measuring plasma current), magnetic probe (measuring external field), diamagnetic loops (measuring <jats:italic>β</jats:italic> <jats:sub> <jats:italic>p</jats:italic> </jats:sub>) and so on. Besides, in order to realize high frequency signal measurement and transmission, a series of frequency response with the magnetic probe and transmission line are tested. Later in the paper, to verify the null field, a fitting code was developed to reconstruct the stray field in vacuum chamber based on measured magnetic probes and flux loops. The result shows the error is within 1.5%. This indicates the accuracy of the magnetic measurement system and ensures the preparation for the breakdown of plasma.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Carbyne is an infinite one-dimensional carbon chain comprising of <jats:italic>sp</jats:italic>-hybridized carbons. Due to its high chemical reactivity and extreme instability, the synthesis and structural diversity of carbyne have been much less investigated in the past decades compared to carbon allotropes built with <jats:italic>sp</jats:italic> <jats:sup>2</jats:sup>-hybridized carbons, such as fullerenes, carbon nanotubes, and graphene. The emerging on-surface synthesis strategy provides an extremely promising approach for the fabrication of novel carbyne-like nanostructures with atomic precision. Herein, we summarize recent exciting progress in the synthesis of carbyne-like nanostructures with one-dimensional <jats:italic>sp</jats:italic>-carbon on surfaces, including polyynes, cumulenes, and organometallic polyynes. We also point out the scientific challenges and prospects, encouraging scientists to explore the fabrication and characterization of single strands of carbyne in this young and promising research field.</jats:p>