Finkroche6159

The Kitaev spin liquid provides a rare example of well-established quantum spin liquids in more than one dimension. It is obtained as the exact ground state of the Kitaev spin model with bond-dependent anisotropic interactions. The peculiar interactions can be yielded by the synergy of spin-orbit coupling and electron correlations for specific electron configuration and lattice geometry, which is known as the Jackeli-Khaliullin mechanism. Based on this mechanism, there has been a fierce race for the materialization of the Kitaev spin liquid over the last decade, but the candidates have been still limited mostly to $4d$- and $5d$-electron compounds including cations with the low-spin $d^5$ electron configuration, such as Ir$^4+$ and Ru$^3+$. Here we discuss recent efforts to extend the material perspective beyond the Jackeli-Khaliullin mechanism, by carefully reexamining the two requisites, formation of the $j_\rm eff=1/2$ doublet and quantum interference between the exchange processes, for not only $d$- but also $f$-electron systems. We present three examples the systems including Co$^2+$ and Ni$^3+$ with the high-spin $d^7$ electron configuration, Pr$^4+$ with the $f^1$-electron configuration, and polar asymmetry in the lattice structure. In particular, the latter two are intriguing since they may realize the antiferromagnetic Kitaev interactions, in contrast to the ferromagnetic ones in the existing candidates. This partial overview would stimulate further material exploration of the Kitaev spin liquids and its topological properties due to fractional excitations. © 2020 IOP Publishing Ltd.We report the first-principles DFT calculation of the electron-hole Lindhard response function of the (TMTSF)2PF6 Bechgaard salt using the real triclinic low-temperature structure. The Lindhard response is found to change considerably with temperature. Near the 2kF spin density wave (SDW) instability it has the shape of a broad triangular plateau as a result of the multiple nesting associated with the warped quasi-one-dimensional Fermi surface. The evolution of the 2kF broad maximum as well as the effect of pressure and deuteration is calculated and analyzed. The thermal dependence of the electron-hole coherence length deduced from these calculations compares very well with the experimental thermal evolution of the 2kF Bond Order Wave correlation length. The existence of a triangular plateau of maxima in the low-temperature electron-hole Lindhard response of (TMTSF)2PF6 should favor a substantial mixing of q-dependent fluctuations which can have important consequences in understanding the phase diagram of the 2kF SDW ground state, the mechanism of superconductivity and the magneto-transport of this paradigmatic quasi-one-dimensional material. The first-principles DFT Lindhard response provides a very accurate and unbiased approach to the low-temperature instabilities of (TMTSF)2PF6 which can take into account in a simple way 3D effects and subtle structural variations, thus providing a very valuable tool in understanding the remarkable physics of molecular conductors. © 2020 IOP Publishing Ltd.Light-activated colloidal assembly and swarming can act as model systems to explore non-equilibrium state of matter. In this context, creating new experimental platforms to facilitate and control two-dimensional assembly of colloidal crystals are of contemporary interest. In this paper, we present an experimental study of assembly of colloidal silica microparticles in the vicinity of a single-crystalline gold microplate evanescently excited by a 532 nm laser beam. The gold microplate acts as a source of heat and establishes a thermal gradient in the system. The created optothermal potential assembles colloids to form a two-dimensional poly-crystal, and we quantify the coordination number and hexagonal packing order of the assembly in such a driven system. Selleckchem C-176 Our experimental investigation shows that for a given particle size, the variation in assembly can be tuned as a function of excitation-polarization and surface to volume ratio of the gold microplates. Furthermore, we observe that the assembly is dependent on size of the particle and its material composition. Specifically, silica colloids assemble but polystyrene colloids do not, indicating an intricate behaviour of the forces under play. Our work highlights a promising direction in utilizing metallic microstructures that can be harnessed for optothermal colloidal crystal assembly and swarming studies. Our experimental system can be utilized to explore optically driven matter and photophoretic interactions in soft-matter including biological systems such as cells and micro organisms. © 2020 IOP Publishing Ltd.Not applicable at Outline stage. Creative Commons Attribution license.Novel supported inorganic metal nano-complexes of Ag(I) and Co(II) derived from 4-amino-N-(4-methylpyrimidin-2-yl) benzene sulfonamide (SulMer) were synthesized using olive leaf extract as reducing agent via grinding as well as microwave methods. The prepared samples denoted as comp1-6. The surface morphology of synthesized nanomaterials were analyzed by C, H, N, S analysis, Fourier-transform infrared spectroscopy, UV visible spectroscopy, Proton and Carbon Nuclear Magnetic Resonance,, SEM, TEM, TGA, and X-ray Powder Diffraction analysis. The data revealed that all the synthesized complexes exhibited 11 metal to ligand ratio with a coordination number of 4 or 6. The mean particle size of nanomaterials samples were with an average size of 25 - 35 nm. XRD patterns indicated a crystalline nature for the complexes. The supported inorganic metal nano-complexes displayed good activity for the adsorptive removal of Direct red 81 (DR-81) from aqueous solutions. On other hand, the studying of the effect of the supported metal nano- complexes on the immune system of the body was determined and how to use these anti-inflammatory compounds to treat many autoimmune diseases, most notably rheumatoid arthritis. Experimental model for arthritis can be induced using Freund's complete adjuvant (CFA). It was shown that the supported complex offer several advantages such stability, eco- friendly, simple experimental conditions, short time reaction, and easy work- up. © 2020 IOP Publishing Ltd.