Theory meets experiment in low-dimensional structures with correlated electrons
Abstract
A great progress in nanotechnology achieved in the last decades stimulated a lot of research activities aimed at a detailed understanding of properties and behaviour of di-verse nanostructures placed on crystalline surfaces with prospects of their applications in electronic devices. Nanosystems containing atoms with open d and f shells (single adatoms , organometallic molecules, small metallic clusters) appear particularly promising for such applications since they display a wide range of complex chemical and physical phenomena. Their rich behaviour comes, at least in part, from strong correlations among the valence electrons, which makes a realistic description of the electronic properties of these systems a challenge. Present-day approximations to the density-functional theory (DFT) are not accurate enough and it is necessary to deal with the correlations in a more explicit manner. In periodic systems, the combination of DFT with the dynamical mean-field theory (DMFT) has turned out to be very fruitful and effective, and the techniques of interfacing the first-principles DFT electronic structure with explicitly correlated models, perfected during development of the LDA+DMFT method, can be, and indeed are, used also in the case of lower-symmetry non-periodic structures represented by nanosystems adsorbed on surfaces. Nevertheless, one needs to be aware of added complications due to reduced dimensionality that affects screening and makes non-local correlations more relevant. It is evident that there is no a robust theoretical methodology available yet which provides reliable description of electronic properties of low dimensional systems with strongly correlated electrons. Indeed, truly comprehensive description of the electronic structure of strongly correlated materials is only possible in tight collaboration between experimental and theoretical groups and using state-of-the-art techniques. Representative methods from the experimental side are scanning-probe methods (for instance spin-flip inelastic electron tunnelling) and valence-band and core-level spectroscopy (XMCD, photoemission, inelastic x-ray scattering) that are able to reveal the magnetic anisotropy and the ground-state symmetry when they are combined with detailed theoretical simulations that go beyond the sum-rule analysis. However, such effort requires to over-come a natural gap between theory and experimental communities, including critical discussion of current limits and challenges in characterization and description of the nanostructures with the strongly correlated electrons. The aim of the proposed workshop is to bring together theoreticians and experimentalists who work on strongly correlated nanosystems adsorbed on surfaces, or on strongly correlated electrons in general, in order to exchange ideas and stimulate new directions of research pertaining to ¥ Single-atom/single-molecule magnets ¥ Transport through nanostructures in and out of the linear-response regime ¥ Tuning the electronic properties via interaction with external stimuli and/or with a substrate ¥ Magnetic anisotropy ¥ Advanced spectroscopies and their theoretical modelling
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 01, 2019
- Source ID
- W911NF1910364
Entities
People
- Pavel Jelínek
Organizations
- Army Contracting Command
- Institute of Physics, Chinese Academy of Sciences
- United States Army