Wave mixing in a three-level quantum system induced by two-photon resonant pump and one-photon resonant coupling at lower transition has been studied theoretically and experimentally. Resonantly enhanced difference-frequency generation efficiency was observed clearly dependent on the time delay and its sign between the femtosecond pump and probe. The role of the atomic coherences on the amplification without inversion during different sequences of interaction in a closed three-level system has been also stressed. These findings were confirmed experimentally in atomic potassium, where strong parametric amplification, induced by the pump delayed with respect to the probe, has been observed for the first time.
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http://dx.doi.org/10.1364/OL.38.000124 | DOI Listing |
Clin Oral Investig
January 2025
Clinic of Conservative and Preventive Dentistry, Center for Dental Medicine, University of Zurich, Zurich, Switzerland.
Objective: Aim of this study was to critically appraise clinical evidence on the potential benefits of adjunctive use of superfoods green tea and turmeric as mouthrinse or local delivery agents in the treatment of periodontal disease.
Materials And Methods: Electronic searches were performed in four databases for randomized trials from inception to February 2024 assessing the supplemental use of superfoods green tea and turmeric for gingivitis/periodontitis treatment. After duplicate study selection, data extraction, and risk-of-bias assessment with the RoB 2 tool, random-effects meta-analyses of Mean Differences (MD) or Standardized Mean Differences (SMD) with their 95% confidence intervals (CI) were performed.
ACS Nano
January 2025
IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120, United States.
Lanthanide atoms show long magnetic lifetimes because of their strongly localized 4 electrons, but electrical control of their spins has been difficult because of their closed valence shell configurations. We achieved electron spin resonance of individual lanthanide atoms using a scanning tunneling microscope to probe the atoms bound to a protective insulating film. The atoms on this surface formed a singly charged cation state having an unpaired 6 electron, enabling tunnel current to access their 4 electrons.
View Article and Find Full Text PDFInorg Chem
January 2025
Institute for Inorganic Chemistry and Center for Sustainable Systems Design (CSSD), Paderborn University, Paderborn 33098, Germany.
A series of Co complexes [Co(ImP)][PF], with HImP = 1,1'-(1,3-phenylene)bis(3-methyl-1-imidazole-2-ylidene)) and R = Me, Et, Pr, Bu, is presented in this work. The influence of the strong donor ligand on the ground and excited-state photophysical properties was investigated in the context of different alkyl substituents at the imidazole nitrogen. X-ray diffraction revealed no significant alterations of the structures and all differences in the series emerge from the electronic structures.
View Article and Find Full Text PDFNano Lett
January 2025
Donostia International Physics Center (DIPC), E-20018 Donostia-San Sebastián, Spain.
Nanoporous graphene (NPG), laterally bonded carbon nanoribbons, is a promising platform for controlling coherent electron propagation in the nanoscale. However, for its successful device integration NPG should ideally be on a substrate that preserves or enhances its anisotropic transport properties. Here, using an atomistic tight-binding model combined with nonequilibrium Green's functions, we study NPG on graphene and show that their electronic coupling is modulated as a function of the interlayer twist angle.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
National Engineering Research Centre for Mg Alloys, Chongqing University, Chongqing 400044, PR China.
Rechargeable Mg batteries are promising candidates for achieving considerable high-energy-density. Enhancing the energy density can be achieved by integrating metallic Mg anodes with conversion-type cathode materials, which are characterized by multi-electron transfer process and elevated specific capacities in contrast to intercalation-type materials. Despite these advantages, the conversion-type cathodes still have some challenges of substantial volume expansion, sluggish diffusion kinetics and intricate mesophase evolution during repeated electrochemical reactions.
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