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The remarkable increase in superconducting transition temperature (T) observed at the interface of one-unit-cell FeSe films on SrTiO substrates (1 uc FeSe/STO) has attracted considerable research into the interface effects. Although this high T is thought to be associated with electron-phonon coupling (EPC), the microscopic coupling mechanism and its role in the superconductivity remain elusive. Here we use momentum-selective high-resolution electron energy loss spectroscopy to atomically resolve the phonons at the FeSe/STO interface. We uncover new optical phonon modes, coupling strongly with electrons, in the energy range of 75-99 meV. These modes are characterized by out-of-plane vibrations of oxygen atoms in the interfacial double-TiO layer and the apical oxygens in STO. Our results also demonstrate that the EPC strength and superconducting gap of 1 uc FeSe/STO are closely related to the interlayer spacing between FeSe and the TiO terminated STO. These findings shed light on the microscopic origin of the interfacial EPC and provide insights into achieving large and consistent T enhancement in FeSe/STO and potentially other superconducting systems.
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http://dx.doi.org/10.1038/s41586-024-08118-0 | DOI Listing |
ACS Nano
September 2025
College of Energy, Soochow Institute for Energy and Materials InnovationS (SIEMIS), Jiangsu Provincial Key Laboratory for Advanced Carbon Materials and Wearable Energy Technologies, Soochow University, Suzhou 215006, China.
The confining walls made by 2D materials are often considered solid boundary conditions in studies of fluid transport through nanochannels, while the atomically thin walls inherently exhibit thermal fluctuations at a finite temperature. In this work, we investigate the solid-liquid interfacial friction properties of water confined within flexible nanochannels using machine-learning-potential molecular dynamics. Surprisingly, we find that the friction coefficient (λ) increases with lateral size in the flexible nanochannels, following a linear relationship with 1/, which is absent in rigid channels.
View Article and Find Full Text PDFJ Phys Condens Matter
September 2025
The Hong Kong Polytechnic University, Hong Kong, Hong Kong, 999077, HONG KONG.
In this review paper, we begin by introducing the fundamental concepts of superconductivity, laying the groundwork for understanding its principles and applications. We then delve into the scientific advantages of one-dimensional (1D) superconductors over three-dimensional (3D) superconductors, highlighting the main significant enhancement in the upper critical field, which can increase by two orders of magnitude. This feature is crucial for advancing the technological performance of superconducting high-field magnets.
View Article and Find Full Text PDFAdv Sci (Weinh)
September 2025
Material Science and Engineering Program (MSE), Physical Sciences and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia.
In conventional semiconductors, electrical and thermal conductivity are typically coupled, posing a challenge in optimizing both simultaneously. Overcoming this inherent trade-off enables strategies for advancing electronic applications. Herein, a strategy is demonstrated to decouple electrical and thermal conductivity trade-off by creating heterostructures of highly conductive single-walled carbon nanotubes (SWCNTs) coated with low conductivity hybrid perovskites.
View Article and Find Full Text PDFNanoscale
September 2025
College of Physics and Electronic Engineering, Center for Computational Sciences, Sichuan Normal University, Chengdu, 610068, China.
Vacancy defects in two-dimensional (2D) materials are not merely structural imperfections but can be strategically engineered to boost and tailor their intrinsic properties. In this work, we propose a novel 2D polymorph of phosphorene, featuring a periodic array of vacancy-derived pentagon-octagon-pentagon (p-o-p) units in blue phosphorene, employing first-principles calculations combined with quasi-particle GW method. Structural optimization, positive phonon modes, mechanical resilience, and thermal stability up to 800 K collectively confirm its structural robustness, flexibility, and potential for experimental realization.
View Article and Find Full Text PDFDalton Trans
September 2025
Jiangsu Key Laboratory for Optoelectronic Detection of Atmosphere and Ocean, Nanjing University of Information Science and Technology, Nanjing, Jiangsu 210044, China.
We propose a dynamically tunable and angle-robust mid-infrared (mid-IR) absorber based on a hybrid metastructure composed of a top-layer Ge grating, an ultrathin SrTiO polar dielectric layer, a thermochromic VO film, and a metallic substrate. The optical response of the system is modeled using rigorous coupled-wave analysis (RCWA), revealing broadband and high-efficiency absorption across a wide range of incident angles (0°-80°) under transverse-magnetic (TM) polarization. The absorption behavior is governed by the interplay of multiple resonant mechanisms, including guided-mode resonance (GMR) in the Ge grating, phonon-polariton (PhP) excitation in the SrTiO layer, and cavity-like modes facilitated by the insulating VO.
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