We extend the Mermin-Wagner theorem to a system of lattice spins which are spin coupled to itinerant and interacting charge carriers. We use the Bogoliubov inequality to rigorously prove that neither (anti-) ferromagnetic nor helical long-range order is possible in one and two dimensions at any finite temperature. Our proof applies to a wide class of models including any form of electron-electron and single-electron interactions that are independent of spin. In the presence of Rashba or Dresselhaus spin-orbit interactions (SOI) magnetic order is not excluded and intimately connected to equilibrium spin currents. However, in the special case when Rashba and Dresselhaus SOIs are tuned to be equal, magnetic order is excluded again. This opens up a new possibility to control magnetism electrically.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.107.107201 | DOI Listing |
Dalton Trans
January 2025
Department of Chemistry, Graduate School of Natural Science and Technology, Shimane University, 1060, Nishikawatsu, Matsue, Shimane, 690-8504, Japan.
Paddlewheel-type diruthenium(II,II) complexes are paramagnetic with two unpaired electrons ( = 1) and can be utilized as versatile building blocks for higher-order structures, such as supramolecular complexes, coordination polymers, and metal-organic frameworks, although they are generally highly air-sensitive. In this study, we developed an air-stable paddlewheel-type diruthenium(II,II) complex with two electron-withdrawing 1,8-naphthyridine-2-carboxylate (npc) ligands, [Ru(μ-npc)(OCMe)] (1). The two acetate ligands in 1 can be replaced by other carboxylate ligands; the solvothermal reactions of 1 with benzoic acid (HOCPh) yields the heteroleptic [Ru(μ-npc)(OCPh)] (2), whereas its reaction with 1,8-naphthyridine-2-carboxylic acid (Hnpc) produces the homoleptic [Ru(μ-npc)(η-npc)] (3).
View Article and Find Full Text PDFAging Cell
January 2025
Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, UK.
Healthy brain aging involves changes in both brain structure and function, including alterations in cellular composition and microstructure across brain regions. Unlike diffusion-weighted MRI (dMRI), diffusion-weighted MR spectroscopy (dMRS) can assess cell-type specific microstructural changes, providing indirect information on both cell composition and microstructure through the quantification and interpretation of metabolites' diffusion properties. This work investigates age-related changes in the higher-order diffusion properties of total N-Acetyl-aspartate (neuronal biomarker), total choline (glial biomarker), and total creatine (both neuronal and glial biomarker) beyond the classical apparent diffusion coefficient in cerebral and cerebellar gray matter of healthy human brain.
View Article and Find Full Text PDFImpact of climate change that stems from gaseous emissions require sustainable materials to eliminate sulfur. This study involves the modification of humic acid with magnetite nanoparticles (Fe₃O₄ NPs) by a microwave-assisted synthesis of an absorbent with reasonable pore volume and diameter for elimination of thiophenic compounds from fuel. The magnetic nano adsorbent designated Fe3O4@HA was characterized using advanced spectroscopic techniques, while their structure and morphology were analyzed through DLS, XPS, XRD, FT-IR, TGA, FESEM-EDX, VSM, and BET-N2 techniques.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
School of Rare Earths, University of Science and Technology of China, Hefei 230026, China.
Achieving ultrahigh permeance and superoleophobicity is crucial for membrane application. Here, we demonstrated that a poly(ionic liquid)/PES hydrogel membrane can achieve dual goals. The high polarity of the ionic liquids induces the water molecules on the membrane surface to be arranged more ordered, as verified by molecular dynamics (MD) simulation and advanced femtosecond sum frequency generation (SFG) vibrational spectroscopy.
View Article and Find Full Text PDFR Soc Open Sci
January 2025
Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford OX3 7DQ, UK.
Atrial fibrillation (AF) is the most prevalent clinical arrhythmia, posing significant mortality and morbidity challenges. Outcomes of current catheter ablation treatment strategies are suboptimal, highlighting the need for innovative approaches. A major obstacle lies in the inability to comprehensively assess both structural and functional remodelling in AF.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!