The quantum anomalous Hall insulator is characterized by a quantized Hall resistance plateau of h/(Ce2) with C being the Chern number. Previously, high-Chern-number insulators with C≥2 that intrinsically suppress the...
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The quantum anomalous Hall insulator is characterized by a quantized Hall resistance plateau of h/(Ce2) with C being the Chern number. Previously, high-Chern-number insulators with C≥2 that intrinsically suppress the energy dissipation in quantized electrical transport have been realized in few-layer MnBi2Te4 nanoflakes under moderate magnetic fields or in Cr-doped topological insulators at extremely low temperatures. It has nevertheless proven elusive to achieve a high-temperature high-Chern-number insulator at zero magnetic field. Here, we demonstrate that the magnetic state in MnBi4Te7 nanoflakes can be consecutively tuned from an antiferromagnetic (AFM) state to an AFM-ferromagnetic (FM) coexistence state, and finally to a robust ferromagnetic (FM) state with large coercivities at temperatures up to 3 K via a protonic gate. This AFM-FM phase transition is well captured by density functional theory simulations that the FM state develops in MnBi4Te7 under hole doping. Notably, we find that the Chern number of FM MnBi4Te7 can be largely tuned not merely by the Zeeman field but also by the sample thickness. Our work demonstrates that gate-tuned MnBi4Te7 nanoflakes hold high potentials for realizing a high-temperature high-Chern-number insulator at zero magnetic field and promising applications in the field of low-energy electronics.
By introducing a discrete Frenet frame, this paper first proposes 3D discrete clothoid splines to extend the planar discrete clothoid splines of Schneider and Kobbelt. On the basis of 3D discrete clothoid spline curve...
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This paper proposes a novel approach to integrate heterogeneous data in P2P networks. The approach includes a tool for building P2P semantic link networks, mechanisms for peer schema mapping, criteria for peer similar...
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ISBN:
(纸本)158113844X
This paper proposes a novel approach to integrate heterogeneous data in P2P networks. The approach includes a tool for building P2P semantic link networks, mechanisms for peer schema mapping, criteria for peer similarity degree measurement, and algorithms for heterogeneous data integration. The approach has three advantages: First, it uses semantic links to describe semantic relationships between peers' data schemas. Second, it deals with the semantic heterogeneity, the structural heterogeneity and the data value inconsistency. Finally, it considers the semantic similarity and structural similarity to forward queries to relevant peers.
With the expansion of the Web, automatically organizing large scale text resources, e.g. Web pages, becomes very important. Many Web sites, like Google and Yahoo, use hierarchical classification trees to organize text...
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Traceability is important for maintaining quality of logistics transactions and improving logistics efficiency. Implementing traceability for cross-border logistics is facing challenges when it lacks global centralize...
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In recent years, semantic search has become one hot motivation of the semantic web. In this paper, we propose a semantic-based resource management and search architecture and its implementation in research community, ...
Knowing semantic links among documents is the basis for intelligent applications over large-scale document resources. Discovering these semantic links with little human interference is a challenge issue. This paper pr...
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Single-shot ultrafast multidimensional optical imaging(UMOI) combines ultrahigh temporal resolution with multidimensional imaging capabilities in a snapshot, making it an essential tool for real-time detection and ana...
Single-shot ultrafast multidimensional optical imaging(UMOI) combines ultrahigh temporal resolution with multidimensional imaging capabilities in a snapshot, making it an essential tool for real-time detection and analysis of ultrafast scenes. However, current single-shot UMOI techniques cannot simultaneously capture the spatial-temporal-spectral complex amplitude information, hampering it from complete analyses of ultrafast *** address this issue, we propose a single-shot spatial-temporal-spectral complex amplitude imaging(STS-CAI)technique using wavelength and time multiplexing. By employing precise modulation of a broadband pulse via an encoding plate in coherent diffraction imaging and spatial-temporal shearing through a wide-open-slit streak camera, dual-mode multiplexing image reconstruction of wavelength and time is achieved, which significantly enhances the efficiency of information acquisition. Experimentally, a custom-built STS-CAI apparatus precisely measures the spatiotemporal characteristics of picosecond spatiotemporally chirped and spatial vortex pulses, respectively. STS-CAI demonstrates both ultrahigh temporal resolution and robust phase sensitivity. Prospectively, this technique is valuable for spatiotemporal coupling measurements of large-aperture ultrashort pulses and offers promising applications in both fundamental research and applied sciences.
Large-field high-resolution electron tomography enables visualizing detailed mechanisms under global structure. As field enlarges, the processing time increases and the distortions in reconstruction become more critic...
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A pilot allocation(PA) scheme is propose to reduce pilot contamination for time division duplex(TDD) massive multiple-input multiple-output(MIMO) system enabled twotier heterogeneous cellular network(Het Net). In orde...
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ISBN:
(纸本)9781509038237;9781509038220
A pilot allocation(PA) scheme is propose to reduce pilot contamination for time division duplex(TDD) massive multiple-input multiple-output(MIMO) system enabled twotier heterogeneous cellular network(Het Net). In order to reduce inter-tier interference during channel estimation, proposed scheme assigns mutually orthogonal pilots between macro-cells and small-cells, and pilots are reused among macro-cells with different pilot reuse factors. Comprehensive analyses and simulations of uplink average signal to interference plus noise ratio(SINR) and average achievable ergodic rate for the proposed scheme are developed. Simulation results show that the proposed PA scheme can reduce pilot contamination and improve the SINR and ergodic rate at base stations(BSs). In addition, the average SINR increases when pilot reuse factor grows, which shows the benefit of the proposed scheme. The average ergodic rate first becomes larger and then becomes smaller when pilot reuse factor becomes larger, which means the large number of pilot symbols limits the increase of ergodic rate.
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