- 标题
- 摘要
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- 实验方案
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True spin and pseudo spin entanglement around Dirac Points in graphene with Rashba spin–orbit interaction
摘要： We analytically obtained the Schmidt decomposition of the entangled state between the pseudo spin and the true spin in graphene with Rashba spin–orbit coupling. The entangled state has the standard form of the Bell state, where the SU(2) spin symmetry is broken. These states can be explicitly expressed as the superposition of two nonorthogonal, but mirror symmetrical spin states entangled with the pseudo spin states. Because of the closely locking between the pseudo spin and the true spin, it is found that the orbit curve in the spin-polarization parameter space for the fixed equi-energy contour around Dirac points has the same shape as the δk-contour. Due to the spin–orbit coupling that cause the topological transition in the local geometry of the dispersion relation, the new equi-energy contours around the new emergent Dirac Points can be obtained by squeezing the one around the original Dirac point. The spin texture in the momentum space around the Dirac points is analyzed under the Rashba spin–orbit interaction and it is found that the orientation of the spin polarization at each crystal momentum k is independent of the Rashba coupling strength.
关键词： Spin texture,Entangled spin states,Rashba spin–orbit interaction
更新于2025-09-23 15:21:21
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New Impressions in Interaction Design: A Task Taxonomy for Elastic Displays
摘要： Novel shape-changing interfaces promise to provide a rich haptic experience for human-computer interaction. As a specific instance of shape-changing interfaces, Elastic Displays provide large interaction surfaces that can be temporally deformed using force-touch. The unique property of these displays is that they automatically return to their initial flat state. Recently, several review and position papers have stimulated a discussion towards consolidating the knowledge about shape-changing interfaces. The knowledge about Elastic Displays is similarly scattered across multiple publications from recent years. This paper contributes a task taxonomy based on productive uses of Elastic Displays found in literature, on the web, and in our interaction lab. This taxonomy emphasizes tasks, but also encompasses general aspects regarding content types, visualization technology, and interaction styles. All aspects of the taxonomy are illustrated using case studies from literature.
关键词： Task Taxonomy,Organic User Interfaces,Human-computer Interaction,Physics-based Interaction,Shape-changing Interfaces,Interaction Design,Tangible Interaction,Elastic Displays
更新于2025-09-23 15:21:01
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The art of laser ablation in aeroengine: The crown jewel of modern industry
摘要： In this perspective, laser interaction with materials and its applications in precision engineering are mainly introduced for the manufacturing, as well as maintenance, repair, and overhaul (MRO) of aeroengines. In precision engineering, the laser ablation tool has also been more applicable considering its great advantages in microprocessing and nanofabrication. It is interesting to explore the specific process and characteristics of laser ablation, which play an important role in advanced manufacturing. Due to the complicated production procedures of an aeroengine, it is important to explore the physics behind laser interaction with aerospace and aeronautical metallic materials in order to properly utilize the unique characteristics of lasers, such as high monochromaticity, high brightness, high directivity, and high coherence. Meanwhile, it is beneficial to study the dynamic process of interactions and its mechanisms in laser applications, such as laser cleaning, texturing, and shock peening. There exist both photo-chemical and photo-thermal processes when lasers and materials interact. Several typical cases are introduced, which have great potential and high impact applications in the manufacturing and MRO industry of aeroengines. Based on laser ablation in specific industries, the building-up of MRO support system for aeroengines could be provided by a dynamic mechanism between the pioneering research results and industrial demand, leading to the fast development of advanced high-end manufacturing equipment.
关键词： precision engineering,laser interaction,aeroengine,MRO,laser ablation
更新于2025-09-23 15:21:01
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Generation of magnetic skyrmions by focused vortex laser pulses
摘要： We propose a method to generate magnetic skyrmions by intense laser pulses optimally focused on a magnetically ordered 2D-layer. In particular, we consider few-cycle intense pulses with the magnetic vortex structure near the focus region on the layer. The spin dynamics is modeled using the Landau–Lifshitz–Gilbert equation and includes the Dzyaloshinskii–Moriya interaction. We demonstrate that skyrmions can be observed within a few picoseconds after the end of the laser pulse. We analyze the physical picture of this process and work out which laser pulse and 2D-layer parameters are required for the generation.
关键词： Dzyaloshinskii–Moriya interaction,laser pulses,Landau–Lifshitz–Gilbert equation,magnetic skyrmions
更新于2025-09-23 15:21:01
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Short range proximity effect induced by exchange interaction in tunnel-coupled CdTe and (Cd,Mn)Te quantum wells
摘要： The coherent spin dynamics of electrons in tunnel-coupled CdTe and (Cd,Mn)Te quantum wells (QWs) is studied by time-resolved pump-probe Kerr rotation. The coupled QWs have different thicknesses; the narrow one is doped by Mn2+ magnetic ions. A short range proximity effect between them is observed: the Zeeman splitting of electrons in the wide QW is given in addition to the intrinsic electron g factor by the exchange interaction with the Mn2+ ions mediated by electron tunneling into the narrow QW. The exchange interaction strength scales with the Cd0.88Mg0.12Te barrier thickness separating the QWs. The Kerr rotation signal measured on the wide QW shows two close frequencies of electron spin Larmor precession in a transverse magnetic field. These components have very different spin dephasing times, 50 ps and 1 ns. The two frequencies originate from electrons in the wide QW being either part of an exciton or being resident. The proximity effect of the exciton electron is smaller due to the binding by Coulomb interaction, which decreases the tunneling to the narrow well. The experimental data are in good agreement with model calculations.
关键词： Kerr rotation,proximity effect,quantum wells,exchange interaction,spin dynamics
更新于2025-09-23 15:21:01
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valley of (In,Al)As/AlAs quantum dots
摘要： The electron-nuclei hyperfine interaction of electrons in indirect band gap (In,Al)As/AlAs quantum dots with type-I band alignment has been experimentally studied by measuring the polarization degree of the photoluminescence in a transverse magnetic field (Hanle effect) and the polarization recovery in a longitudinal magnetic field. The different symmetries of the X valley electron Bloch amplitudes at the As, In, and Al nuclei strongly affect the hyperfine interaction. The hyperfine constants corresponding to these nuclei have been determined.
关键词： X valley,hyperfine constants,Bloch amplitudes,Hanle effect,polarization recovery,photoluminescence,quantum dots,electron-nuclei hyperfine interaction
更新于2025-09-23 15:21:01
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Pulse control in self-mode-locked 2.8???μm Er-doped fluoride fiber lasers
摘要： In this work, it had been demonstrated that the Er doped fluoride fiber laser emitting at 2.8 μm could accomplish the dark pulse based on self-mode-locked (SML). And the different distances of external feedback were also investigated in experiment. It was found that signal-noise ratio (SNR) of fundamental cavity repetition rate was decreased with increasing the distance of feedback. It was not only caused by increasing the length of cavity, but also influenced by the interaction between inter-cavity and external cavity. The fundamental cavity repetition rate of SML 2.8 μm pulsed laser could be controlled by adjusting distance of external feedback.
关键词： Cavity interaction,Self-mode-locked fiber laser,Dark pulse,Er-doped fluoride fiber
更新于2025-09-23 15:21:01
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Switchable All-Optical Flip-Flop and Inverter Operations in Quantum Well Microring Laser
摘要： In this paper, distributed time-varying formation (TVF) control problems for general linear swarm systems with switching interaction topologies are investigated using an adaptive dynamic protocol. First, a TVF control protocol for switching interaction topologies is constructed using the states of neighboring agents. In the protocol, an adaptive controller that employs gain scheduling technique is provided to estimate the coupling weights among agents. Compared with the previous studies on formation control, the desired formation can be specified by piecewise continuously time-varying differentiable vectors, the interaction topology can be switching, and the disadvantage of requiring global information of the interaction topologies is removed in this paper. Then, an algorithm including a feasible formation condition is proposed to determine the gain matrices of the distributed adaptive formation protocol by solving a linear matrix inequality for swarm systems with switching interaction topologies. Moreover, under the designed distributed adaptive formation protocol, sufficient condition for general linear swarm systems with switching interaction topologies to achieve the given TVF is derived using the Lyapunov theory. Finally, numerical simulations are presented to demonstrate the obtained results.
关键词： general linear dynamics,Distributed adaptive protocol,time-varying formation,swarm systems,switching interaction topology
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - GaAs/Si Double-Junction Cells Fabricated by Sacrificial Layer Etching of Directly-Bonded III-V/Si Junctions
摘要： Wireless distributed storage systems can potentially relieve the centralized traffic burden of base stations (BSs), and further improve system reliability for content sharing in device-to-device (D2D) communications. Mobile devices [i.e., content requesters (CRs)] can not only download their desired contents from serving BSs, but can also get them from neighboring devices [i.e., content helpers (CHs)] with possession of the contents. However, D2D links between CRs and CHs are not necessarily stable, due to user mobility and the time-varying property of wireless links. This paper focuses on the utilization of socially enabled D2D links to deliver the desired contents based on distributed storage. We evaluate the success rate for downloading and repairing in D2D-assisted networks accordingly, by analyzing statistic social interaction information for potential D2D links. Thus, it is necessary to maintain or assign enough qualified D2D links to afford content downloading and repairing from neighboring devices. To reduce the overall system transmission cost, this paper further proposes a hierarchical bi-partite method to guarantee at least k admissible D2D links according to their statistical channel state information, by considering one type of erasure correcting codes, the maximum distance separable code. Simulation results demonstrate the performance and advantage of our proposed scheme.
关键词： D2D communications,social interaction,Wireless distributed storage,maximum distance separable code
更新于2025-09-23 15:21:01
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Porosity-Controllable Magnetoplasmonic Nanoparticles and Their Assembled Arrays
摘要： Control of the chemical and physical properties of nanoscale colloids and their nanoassemblies remains a challenging issue for enhancing the performance and functionalities of nanodevices. In this study, we report a post-synthesis etching method to tailor the porosity of the Fe3O4 shells coating on Ag NPs, establishing a facile but effective approach to regulate the chemical and optical properties of the colloids and their assembled structures. As the shell porosity increases, the NPs are transformed, producing enhanced catalytic activity and the surface-enhanced Raman spectroscopy (SERS) effect, which results from enhanced chemical diffusion into the Ag core. Magnetoplasmonic (MagPlas) one- (1D) and two- (2D) dimensional arrays fabricated using these porosity-controllable NPs exhibit intriguing plasmon properties that are strongly affected by the porosity of the particle shell. Furthermore, the bright coloration of the 2D arrays is tuned by changing the shell porosity or introducing an additional metallic layer. Such 1D and 2D porous MagPlas metastructures possessing Fe3O4 shells with tunable porosities are a fulcrum for developing recyclable catalysts and tunable optical filters with optimized activity, selectivity, and sensitivity, as well as color displays and sensing platforms.
关键词： coloration,porosity,metamaterial,plasmon interaction,magnetoplasmonic
更新于2025-09-23 15:21:01