Compact terahertz (THz) functional devices are greatly sought after for high-speed wireless communication, biochemical sensing, and non-destructive inspection. However, controlled THz generation, along with transport and detection, has remained a challenge especially for chip-scale devices due to low-coupling efficiency and unavoidable absorption losses. Here, based on the topological protection of electromagnetic waves, we demonstrate nonlinear generation and topologically tuned confinement of THz waves in an engineered lithium niobate chip forming a wedge-shaped Su-Schrieffer-Heeger lattice. Experimentally measured band structures provide direct visualization of the THz localization in the momentum space, while robustness of the confined mode against chiral perturbations is also analyzed and compared for both topologically trivial and nontrivial regimes. Such topological control of THz waves may bring about new possibilities in the realization of THz integrated circuits, promising for advanced photonic applications.
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http://dx.doi.org/10.1038/s41377-022-00823-7 | DOI Listing |
Neural Netw
January 2025
Chongqing Key Laboratory of Computational Intelligence, Chongqing University of Posts and Telecommunications, Chongqing, 400065, China; College of Computer and Information Science, Chongqing Normal University, Chongqing, 401331, China. Electronic address:
The production of expressive molecular representations with scarce labeled data is challenging for AI-driven drug discovery. Mainstream studies often follow a pipeline that pre-trains a specific molecular encoder and then fine-tunes it. However, the significant challenges of these methods are (1) neglecting the propagation of diverse information within molecules and (2) the absence of knowledge and chemical constraints in the pre-training strategy.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha No 10, Bandung 40132, Jawa Barat, Indonesia.
The magnetic, electronic, and topological properties of GdPtBi were systematically investigated using first-principles density functional theory (DFT) calculations. Various magnetic configurations were examined, including ferromagnetic (FM) and antiferromagnetic (AFM) states, with particular focus on AFM states where the Gd magnetic moments align either parallel (AFM) or perpendicular (AFM) to the [111] crystal direction. For AFM, the in-plane angles were varied at = 0°, 15°, and 30° (denoted as AFM, AFM, and AFM, respectively).
View Article and Find Full Text PDFMater Horiz
January 2025
Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, 2500, Australia.
Recently, the emergence of two-dimensional (2D) multiferroic materials has opened a new perspective for exploring topological states. However, instances of tuning topological phase transitions through ferroelectric (FE) polarization in 2D ferromagnetic (FM) materials are relatively rare. Here, we found that 11 single layer (SL) materials, named the MMGeX family, possess both FE and FM properties.
View Article and Find Full Text PDFNat Commun
December 2024
Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China.
The emergence of single-atom catalysts offers exciting prospects for the green production of hydrogen peroxide; however, their optimal local structure and the underlying structure-activity relationships remain unclear. Here we show trace Fe, up to 278 mg/kg and derived from microbial protein, serve as precursors to synthesize a variety of Fe single-atom catalysts containing FeNO (1 ≤ x ≤ 4) moieties through controlled pyrolysis. These moieties resemble the structural features of nonheme Fe-dependent enzymes while being effectively confined on a microbe-derived, electrically conductive carbon support, enabling high-current density electrolysis.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Materials, Imperial College London, London, SW7 2AZ, UK.
Topological Insulators (TIs) are promising platforms for Quantum Technology due to their topologically protected surface states (TSS). Plasmonic excitations in TIs are especially interesting both as a method of characterisation for TI heterostructures, and as potential routes to couple optical and spin signals in low-loss devices. Since the electrical properties of the TI surface are critical, tuning TI surfaces is a vital step in developing TI structures that can be applied in real world plasmonic devices.
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