Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title> <jats:p>Benefiting from the well adjustability and the strong near-field enhancement, surface plasmons are widely used for optical force trap and achieve great performance. Here, we employ the Laguerre-Gaussian beam and a plasmonic gold ring to separate enantiomers by the chiral optical force. Along with the radial optical force that traps the particles, there is also a chirality-sign-sensitive lateral force arising from the optical spin angular momentum, which is caused by the interaction of optical orbit angular momentum and gold ring structure. By selecting a specific incident wavelength, the strong angular scattering and non-chiral related azimuthal optical force can be suppressed. Thus the chiral related azimuthal optical force can induce an opposite orbital rotation of the trapped particles with chirality of different sign near the gold ring. This work proposes an effective approach for catching as well as separating chiral enantiomers.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We theoretically investigate a second-order optomechanical induced transparency(OMIT) process of a hybrid optomechanical system (COMS), which a Bose-Einstein condensate (BEC) in the presence of atom-atom interaction trapped inside a cavity with a moving end mirror. The advantage of this hybrid COMS over a bare COMS is that the frequency of the second mode is controlled by the s-wave scattering interaction. Based on the traditional linearization approximation, we derive analytical solutions for the output transmission intensity of the probe field and the dimensionless amplitude of the second-order sideband(SS). The numerical results show that the transmission intensity of the probe field and the dimensionless amplitude of the SS can be controlled by the s-wave scattering frequency. Furthermore, the control field intensities, the effective detuning, the effective coupling strength of the cavity field with the Bogoliubov mode are used to control the transmission intensity of the probe field and the dimensionless amplitude of the SS.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Quantum key distribution (QKD) generates information-theoretical secure keys between two parties based on the physical laws of quantum mechanics. The Phase-Matching (PM) QKD protocol allows the key rate to break the quantum channel secret key capacity limit without quantum repeaters, and the security of the protocol is demonstrated by using equivalent entanglement. In this paper, the Wavelength Division Multiplexing (WDM) technique is applied to the PM-QKD protocol considering the effect of crosstalk noise on the secret key rate. The performance of PM-QKD protocol based on WDM with the influence of adjacent classical channels and Raman scattering is analyzed by numerical simulations to maximize the total secert key rate of the QKD, providing a reference for future implementations of QKD based on WDM techniques.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>As the microwave generator, the spin transfer nano-oscillator (STNO) based on skyrmion is promising to be one of the next generation spintronic devices. However, there still exist a few limitations to the possibility for practical application. In this paper, we propose a new STNO based on synthetic antiferromagnetic (SAF) skyrmion pair assisted by perpendicular fixed magnetic field. It is found that the oscillation frequency of this kind of STNO can reach up to 5.0 GHz, and multiple oscillation peak with higher frequency can be realized under fixed out-of-plane magnetic field. Further investigation showed that the skyrmion stability is improved by bilayer antiferromagnetic coupling, which guarantee the stability process of skyrmion under higher spin polarized current density. Our results provide the alternative possibilities for designing new skyrmion-based STNO to further improving the oscillation frequency, and realizing the output of multiple frequency microwave signal.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>One dimensional s-wave superconductor with spin-orbit coupling is a platform for the realization of Majorana zero modes. The spin-exchange with the magnetic skyrmion lattice can induce spin-orbit coupling in a s-wave superconductor system and the effects are different from the constant spin-orbit coupling. The strength of the effective spin-orbit coupling as well as the rich topoloigcal phase diagram are directly connected to the radius of the skyrmion lattice <jats:italic>R</jats:italic>. We obtain the rich topological phase diagram of this system with different skyrmion lattice radius by numerically evaluate the spectrum of the system in the periodic boundary condition, and we also find the Majorana zero modes in the open boundary condition to verify the bulk-edge corespondence.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Clear imaging of surface plasmon polaritons (SPPs) is a prerequisite for SPPs-based applications. In this paper, we demonstrated an improvement of near field imaging of SPPs via directly comparing the visibility of the photoemission electron microscopy (PEEM) image of SPPs under one- and two-color laser excitation (also known as one- or two-color laser PEEM). By measuring the photoelectron yield and the contrast of the interference fringes of SPPs, we demonstrate that, in addition to enhancing the photoemission yield, two-color laser PEEM can significantly improve the contrast between bright and dark fringe (nearly 4 times higher than that of one-color laser case). By recording the nonlinear order of the photoelectrons ejected from the bright and dark fringes, respectively, the underlying mechanism for the improved visibility is revealed. In addition, the influence of the polarization direction of 400 nm laser on the PEEM images of the SPPs with different wave vector directions is shown. These results can provide technical support for the development of SPPs-based communication devices and catalysis.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Natural and artificially prepared nanorods surfaces have been proved to have good bactericidal effect and self-cleaning property. In order to investigate whether nanorods can kill the enveloped virus, like destroying bacterial cell, we studied the interaction between nanorods and virus envelope by establishing the models of nanorod with different sizes as well as the planar membrane and vesicle under the Dry Martini force field of molecular dynamics simulation. The results show that due to the van der Waals attraction between nanorods and the tail hydrocarbon chain groups of phospholipid molecules, the phospholipid molecules on virus envelope are adsorbed to nanorods on a large scale. This process will increase the surface tension of lipid membrane and reduce the order of lipid molecules, resulting in irreparable damage to planar lipid membrane. Nanorods with different diameters have different effects on vesicle envelope, the larger the diameter of nanorod, the weaker the van der Waals effect on the unit cross-sectional area, and the smaller the degree of vesicle deformation. There is synergy between the nanorods in the nanorod array, which can enhance the speed and scale of lipid adsorption. The vesicle adsorbed in the array are difficult to desorb, and even if desorbed, vesicle will be seriously damaged. The deformation rate of the vesicle adsorbed in the nanorod array exceeds 100%, implying that the nanorod array has a strong destructive effect on the vesicle. This preliminarily proves the feasibility of nanorod array on a surface against enveloped virus, and provides a reference for the design of corresponding nanorods surface.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Here we propose a hybrid polymer-LN waveguide for achieving phase-matched second-harmonic generation (SHG). From the aspect of super-mode theory, the geometric parameters of the hybrid semi-nonlinear waveguide were optimized to utilize both symmetric (even) and antisymmetric (odd) modes of the pump and SHG waves so as to facilitate phase matching with large modal overlap. Phase matching between a fundamental even (TE<jats:sub>00</jats:sub>-like) mode at 1320 nm and a fundamental odd (TE<jats:sub>01</jats:sub>-like) mode at 660 nm was found with a calculated modal overlap integral of 0.299, while utilizing the largest nonlinear coefficient <jats:italic>d</jats:italic> <jats:sub>33</jats:sub>, and achieving an efficient calculated normalized conversion efficiency of 148% W<jats:sup>-1</jats:sup>cm<jats:sup>-2</jats:sup>. Considering the fabrication feasibility of such hybrid waveguide with features including etchless, large dimension and low structural sensitivity, we believe our findings would provide a useful reference for future on-chip efficient nonlinear conversion devices.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The cavitation dynamics and its mechanical stress in viscoelastic tissues, as the primary mechanisms of some ultrasound therapies, would be extremely complex due to the interactions of cavitation bubble with nearby bubbles and surrounding tissues. Therefore, the cavitation dynamics and resultant mechanical stress of two-interacting bubbles in the viscoelastic tissues are numerically investigated, especially focusing on the effects of the nearby bubble. The results demonstrate that the mechanical stress is highly dependent on the bubble dynamics. The compressive and tensile stresses are generated at the stages of bubble expansion and collapse, respectively. Furthermore, within the initial parameters examined in this paper, the effects of the nearby bubble would distinctly suppress the cavitation dynamics of the small bubble and consequently lead to a decrease in its associated stresses. Due to the superimposition of two stress fields, the mechanical stresses surrounding the small bubble in the direction of the neighboring bubble are smaller than those in other directions. For two interacting cavitation bubbles, the suppression effects of the nearby bubble on both the cavitation dynamics and the stresses surrounding the small bubble increase as the ultrasound amplitude and the initial radius of the large bubble increase, whereas they decrease with the inter-bubble distance increasing. Moreover, increasing the tissue viscoelasticity would reduce the suppression effects of the nearby bubble, except in instances where the compressive and tensile stresses first increase and then decrease with the tissue elasticity and viscosity increasing respectively. This study might provide a further understanding on the mechanisms of cavitation-associated mechanical damage on the nearby tissues or cells.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>This work related to the In segregation and its suppression in InGaAs/AlGaAs quantum well is investigated using high-resolution XRD and PL, combined with the state-of-the-art aberration corrected scanning transmission electron microscopy (Cs-STEM) techniques. To facility our study, we grow two multiple quantum wells (MQWs) samples, which are almost identical except that in sample B that a thin GaAs layer is inserted in each of the InGaAs well and AlGaAs barrier layer comparing to pristine InGaAs/AlGaAs MQWs (sample A). Our study indeed shows the direct evidences that In segregation occurs in the InGaAs/AlGaAs interface, and the effect of the GaAs insertion layer on suppressing the segregation of In atoms is also demonstrated in the atomic-scale. Therefore, the atomic-scale insights are provided to understand the segregation behavior of In atoms and to unravel the underlying mechanism of the effect of GaAs insertion layer on the improvement of crystallinity, interface roughness, and further an enhanced optical performance of InGaAs/AlGaAs QWs.</jats:p>