SwePub - search: WFRF:(Katsnelson M)

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1.	Ferrari, A. C., et al. (author) Science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems 2015 In: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3372 .- 2040-3364. ; 7:11, s. 4598-4810 Journal article (peer-reviewed)abstract We present the science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems, targeting an evolution in technology, that might lead to impacts and benefits reaching into most areas of society. This roadmap was developed within the framework of the European Graphene Flagship and outlines the main targets and research areas as best understood at the start of this ambitious project. We provide an overview of the key aspects of graphene and related materials (GRMs), ranging from fundamental research challenges to a variety of applications in a large number of sectors, highlighting the steps necessary to take GRMs from a state of raw potential to a point where they might revolutionize multiple industries. We also define an extensive list of acronyms in an effort to standardize the nomenclature in this emerging field.
2.	Bischoff M. M. J., Fang C. M. , De Groot R. A. , Heijnen G. M. M. , Katsnelson M. I. , Kolesnychenko O. Yu. , De Kort R. , Lichtenstein A. I. , Quinn A. J. , de Parma A. L. V. , Yamada T. K. , and Van Kempen H. (author) Scanning tunneling spectroscopy study of surface states of 3d metals: Chemical identification, magnetic contrast and orbital Kondo resonance states 2003 In: Acta Physica Polonica A. ; , s. 231- Conference paper (peer-reviewed)
3.	Boukhvalov D. W., Kurmaev E. Z. , Moewes A. , Zatsepin D. A., Cherkashenko V. M., Nemnonov S. N., Finkelstein L. D. , Yarmoshenko Yu. M., Neumann M., Dobrovitski V. V. , Katsnelson M. I. , Lichtenstein A. I. , Harmon B. N. , Kögerler P. (author) Electronic structure of magnetic molecules V15: LSDA+U calculations, X-ray emission and photoelectron spectra 2003 In: Physical Review B. ; 67, s. 134408- Journal article (peer-reviewed)
4.	Dubrovinsky, L., et al. (author) The most incompressible metal osmium at static pressures above 750 gigapascals 2015 In: Nature. - : NATURE PUBLISHING GROUP. - 0028-0836 .- 1476-4687. ; 525:7568, s. 226- Journal article (peer-reviewed)abstract Metallic osmium (Os) is one of the most exceptional elemental materials, having, at ambient pressure, the highest known density and one of the highest cohesive energies and melting temperatures(1). It is also very incompressible(2-4), but its high-pressure behaviour is not well understood because it has been studied(2-6) so far only at pressures below 75 gigapascals. Here we report powder X-ray diffraction measurements on Os at multi-megabar pressures using both conventional and double-stage diamond anvil cells(7), with accurate pressure determination ensured by first obtaining self-consistent equations of state of gold, platinum, and tungsten in static experiments up to 500 gigapascals. These measurements allow us to show that Os retains its hexagonal close-packed structure upon compression to over 770 gigapascals. But although its molar volume monotonically decreases with pressure, the unit cell parameter ratio of Os exhibits anomalies at approximately 150 gigapascals and 440 gigapascals. Dynamical mean-field theory calculations suggest that the former anomaly is a signature of the topological change of the Fermi surface for valence electrons. However, the anomaly at 440 gigapascals might be related to an electronic transition associated with pressure-induced interactions between core electrons. The ability to affect the core electrons under static high-pressure experimental conditions, even for incompressible metals such as Os, opens up opportunities to search for new states of matter under extreme compression.
5.	McArdle, P. F., et al. (author) Agreement between TOAST and CCS ischemic stroke classification: The NINDS SiGN Study 2014 In: Neurology. - 0028-3878 .- 1526-632X. ; 83:18, s. 1653-60 Journal article (peer-reviewed)abstract OBJECTIVE: The objective of this study was to assess the level of agreement between stroke subtype classifications made using the Trial of Org 10172 Acute Stroke Treatment (TOAST) and Causative Classification of Stroke (CCS) systems. METHODS: Study subjects included 13,596 adult men and women accrued from 20 US and European genetic research centers participating in the National Institute of Neurological Disorders and Stroke (NINDS) Stroke Genetics Network (SiGN). All cases had independently classified TOAST and CCS stroke subtypes. Kappa statistics were calculated for the 5 major ischemic stroke subtypes common to both systems. RESULTS: The overall agreement between TOAST and CCS was moderate (agreement rate, 70%; κ = 0.59, 95% confidence interval [CI] 0.58-0.60). Agreement varied widely across study sites, ranging from 28% to 90%. Agreement on specific subtypes was highest for large-artery atherosclerosis (κ = 0.71, 95% CI 0.69-0.73) and lowest for small-artery occlusion (κ = 0.56, 95% CI 0.54-0.58). CONCLUSION: Agreement between TOAST and CCS diagnoses was moderate. Caution is warranted when comparing or combining results based on the 2 systems. Replication of study results, for example, genome-wide association studies, should utilize phenotypes determined by the same classification system, ideally applied in the same manner.
6.	Boukhvalov, D. W., et al. (author) Electronic structure of a Mn-12 molecular magnet : Theory and experiment 2007 In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 75:1, s. 014419- Journal article (peer-reviewed)abstract We used site-selective and element-specific resonant inelastic x-ray scattering (RIXS) to study the electronic structure and the electron interaction effects in the molecular magnet [Mn12O12(CH3COO)(16)(H2O)(4)]center dot 2CH(3)COOH center dot 4H(2)O, and compared the experimental data with the results of local spin density approximation +U electron structure calculations which include the on-site Coulomb interactions. We found a good agreement between theory and experiment for the Coulomb repulsion parameter U = 4 eV. In particular, the p-d band separation of 1.8 eV has been found from the RIXS spectra, which is in accordance with the calculations. Similarly, the positions of the peaks in the XPS spectra agree with the calculated densities of p and d states. Using the results of the electronic structure calculations, we determined the intramolecular exchange parameters, and used them for diagonalization of the Mn-12 spin Hamiltonian. The calculated exchanges gave the correct ground state with the total spin S = 10.
7.	Colarieti-Tosti, M., et al. (author) First-Principles Theory of Intermediate Valence f-electron systems In: Physical Review Letters. Journal article (peer-reviewed)
8.	Glazyrin, K., et al. (author) Importance of Correlation Effects in hcp Iron Revealed by a Pressure-Induced Electronic Topological Transition 2013 In: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 110:11, s. 117206- Journal article (peer-reviewed)abstract We discover that hcp phases of Fe and Fe0.9Ni0.1 undergo an electronic topological transition at pressures of about 40 GPa. This topological change of the Fermi surface manifests itself through anomalous behavior of the Debye sound velocity, c/a lattice parameter ratio, and Mossbauer center shift observed in our experiments. First-principles simulations within the dynamic mean field approach demonstrate that the transition is induced by many-electron effects. It is absent in one-electron calculations and represents a clear signature of correlation effects in hcp Fe.
9.	Link, S., et al. (author) Introducing strong correlation effects into graphene by gadolinium intercalation 2019 In: Physical Review B. - 2469-9950. ; 100:12 Journal article (peer-reviewed)abstract Exotic ordered ground states driven by electronic correlations are expected to be induced in monolayer graphene when doped to the Van Hove singularity. Such doping levels are reached by intercalating Gd in graphene on SiC(0001), resulting in a strong homogeneity and stability. The electronic spectrum now exhibits severe renormalizations. Flat bands develop which are driven by electronic correlations according to our theoretical studies. Due to strong electron-phonon coupling in this regime, polaron replica bands develop. Thus, interesting ordered ground states should be made accessible.
10.	Locht, Inka L. M., et al. (author) Standard model of the rare earths analyzed from the Hubbard I approximation 2016 In: PHYSICAL REVIEW B. - : American Physical Society. - 2469-9950. ; 94:8 Journal article (peer-reviewed)abstract In this work we examine critically the electronic structure of the rare-earth elements by use of the so-called Hubbard I approximation. From the theoretical side all measured features of both occupied and unoccupied states are reproduced, without significant deviations between observations and theory. We also examine cohesive properties like the equilibrium volume and bulk modulus, where we find, in general, a good agreement between theory andmeasurements. In addition, we have reproduced the spin and orbital moments of these elements as they are reflected from measurements of the saturation moment. We have also employed the Hubbard I approximation to extract the interatomic exchange parameters of an effective spin Hamiltonian for the heavy rare earths. We show that the Hubbard I approximation gives results which are consistent with calculations where 4f electrons are treated as core states for Gd. The latter approach was also used to address the series of the heavy/late rare earths. Via Monte Carlo simulations we obtained ordering temperatures which reproduce measurements within about 20%. We have further illustrated the accuracy of these exchange parameters by comparing measured and calculated magnetic configurations for the heavy rare earths and the magnon dispersion for Gd. The Hubbard I approximation is compared to other theories of the electronic structure, and we argue that it is superior. We discuss the relevance of our results in general and how this makes it possible to treat the electronic structure of materials containing rare-earth elements, such as permanent magnets, magnetostrictive compounds, photovoltaics, optical fibers, topological insulators, and molecular magnets.
11.	Locht, Inka L. M., et al. (author) The standard model of the rare-earths, analyzed from the Hubbard-Iapproximation Other publication (other academic/artistic)
12.	Niklasson, A. M. N., et al. (author) Modeling the actinides with disordered local moments 2003 In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 67, s. 235105- Journal article (peer-reviewed)
13.	Sokolewicz, R. J., et al. (author) Gilbert damping in two-dimensional metallic antiferromagnets 2024 In: Physical Review B. - : American Physical Society. - 2469-9950 .- 2469-9969. ; 109:13 Journal article (peer-reviewed)abstract A finite spin life-time of conduction electrons may dominate Gilbert damping of two-dimensional metallic antiferromagnets or antiferromagnet / metal heterostructures. We investigate the Gilbert damping tensor for a typical low-energy model of a metallic antiferromagnet system with honeycomb magnetic lattice and Rashba spinorbit coupling for conduction electrons. We distinguish three regimes of spin relaxation: exchange-dominated relaxation for weak spin -orbit coupling strength, Elliot-Yafet relaxation for moderate spin -orbit coupling, and Dyakonov-Perel relaxation for strong spin -orbit coupling. We show, however, that the latter regime takes place only for the in -plane Gilbert damping component. We also show that anisotropy of Gilbert damping persists for any finite spin -orbit interaction strength provided we consider no spatial variation of the N & eacute;el vector. Isotropic Gilbert damping is restored only if the electron spin -orbit length is larger than the magnon wavelength. Our theory applies to MnPS 3 monolayer on Pt or to similar systems.
14.	Wessely, O., et al. (author) Comparison of X-ray absorption spectroscopy calculations on water and ice using transition-potential and Mahan-Nozières-De Dominicis theory Other publication (other academic/artistic)
15.	Ay, Hakan, et al. (author) Pathogenic Ischemic Stroke Phenotypes in the NINDS-Stroke Genetics Network 2014 In: Stroke. - 0039-2499. ; 45:12, s. 3589-3596 Journal article (peer-reviewed)abstract BACKGROUND AND PURPOSE: NINDS (National Institute of Neurological Disorders and Stroke)-SiGN (Stroke Genetics Network) is an international consortium of ischemic stroke studies that aims to generate high-quality phenotype data to identify the genetic basis of pathogenic stroke subtypes. This analysis characterizes the etiopathogenetic basis of ischemic stroke and reliability of stroke classification in the consortium. METHODS: Fifty-two trained and certified adjudicators determined both phenotypic (abnormal test findings categorized in major pathogenic groups without weighting toward the most likely cause) and causative ischemic stroke subtypes in 16954 subjects with imaging-confirmed ischemic stroke from 12 US studies and 11 studies from 8 European countries using the web-based Causative Classification of Stroke System. Classification reliability was assessed with blinded readjudication of 1509 randomly selected cases. RESULTS: The distribution of pathogenic categories varied by study, age, sex, and race (P<0.001 for each). Overall, only 40% to 54% of cases with a given major ischemic stroke pathogenesis (phenotypic subtype) were classified into the same final causative category with high confidence. There was good agreement for both causative (κ 0.72; 95% confidence interval, 0.69-0.75) and phenotypic classifications (κ 0.73; 95% confidence interval, 0.70-0.75). CONCLUSIONS: This study demonstrates that pathogenic subtypes can be determined with good reliability in studies that include investigators with different expertise and background, institutions with different stroke evaluation protocols and geographic location, and patient populations with different epidemiological characteristics. The discordance between phenotypic and causative stroke subtypes highlights the fact that the presence of an abnormality in a patient with stroke does not necessarily mean that it is the cause of stroke.
16.	Baglai, Mikhail, et al. (author) Giant anisotropy of Gilbert damping in a Rashba honeycomb antiferromagnet 2020 In: Physical Review B. - : American Physical Society. - 2469-9950 .- 2469-9969. ; 101:10 Journal article (peer-reviewed)abstract Giant Gilbert damping anisotropy is identified as a signature of strong Rashba spin-orbit coupling in a two-dimensional antiferromagnet on a honeycomb lattice. The phenomenon originates in spin-orbit-induced splitting of conduction electron subbands that strongly suppresses certain spin-flip processes. As a result, the spin-orbit interaction is shown to support an undamped nonequilibrium dynamical mode that corresponds to an ultrafast in-plane Neel vector precession and a constant perpendicular-to-the-plane magnetization. The phenomenon is illustrated on the basis of a two-dimensional s-d-like model. Spin-orbit torques and conductivity are also computed microscopically for this model. Unlike Gilbert damping, these quantities are shown to reveal only a weak anisotropy that is limited to the semiconductor regime corresponding to the Fermi energy staying in the close vicinity of the antiferromagnetic gap.
17.	Boukhvalov, D.W., et al. (author) Testing the magnetism of polymerized fullerene 2004 In: Physical Review B. ; 69:11, s. 115425- Journal article (peer-reviewed)
18.	Carbone, C., et al. (author) Correlated Electrons Step by Step : Itinerant-to-Localized Transition of Fe Impurities in Free-Electron Metal Hosts 2010 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 104:11, s. 117601- Journal article (peer-reviewed)abstract High-resolution photoemission spectroscopy and ab initio calculations have been employed to analyze the onset and progression of d-sp hybridization in Fe impurities deposited on alkali metal films. The interplay between delocalization, mediated by the free-electron environment, and Coulomb interaction among d electrons gives rise to complex electronic configurations. The multiplet structure of a single Fe atom evolves and gradually dissolves into a quasiparticle peak near the Fermi level with increasing host electron density. The effective multiorbital impurity problem within the exact diagonalization scheme describes the whole range of hybridizations.
19.	Colarieti-Tosti, Massimiliano, et al. (author) First-principles theory of intermediate-valence f-electron systems 2004 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 93:9, s. 096403- Journal article (peer-reviewed)abstract We propose a first-principles based method for calculating the electronic structure and total energy of solids in an intermediate-valence configuration. The method takes into account correlation effects (d-f Coulomb interaction) and many-body renormalization of the effective hybridization parameter of the f system. As an example, the formation of a pressure-induced intermediate-valence state in Yb is considered and its electronic structure and equation of state are calculated and compared to experimental data. The agreement is found to be excellent for both properties, and we argue that the developed method, which applies to any element or compound, provides for the first time a quantitative theoretical treatment of intermediate-valence materials.
20.	Dallera, C., et al. (author) Understanding mixed valent materials : Effects of dynamical core-hole screening in high-pressure x-ray spectroscopy 2006 In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 74:8, s. 081101- Journal article (peer-reviewed)abstract Changes in the electronic structure of Yb, a material whose valence is modified under pressure, are observed with remarkable detail in x-ray absorption and emission data measured between ambient conditions and 20 GPa. These changes are reproduced by a theory that essentially does not rely on experimental parameters, and includes dynamical core-hole screening. From the combined experimental and theoretical data we can firmly establish on a quantitative level how the valency of an intermediate valence material is modified by pressure. In metallic Yb it increases from 2 to 2.55 +/- 0.05 between 0 and 20 GPa.
21.	de Raedt H. A., Hams A. H., Dobrovitski V. V., Al-Sager M., Katsnelson M. I., Harmon B. N. (author) Many-spin effects and tunneling splittings in Mn12 magnetic molecules 2002 In: Journal of Magnetism and Magnetic Materials. ; 246, s. 392- Journal article (peer-reviewed)
22.	De Raedt, H.A., et al. (author) Many-spin calculation of tunneling splittings in Mn12 magnetic molecules 2002 In: J. Appl. Phys.. ; 91, s. 7152- Journal article (other academic/artistic)
23.	Kurmaev, E Z, et al. (author) Half-metallic electronic structure of CrO2 in resonant scattering 2003 In: Physical Review B. ; 67:15, s. 155105- Journal article (peer-reviewed)
24.	Peters, L., et al. (author) Valence and spectral properties of rare-earth clusters 2015 In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 92:3 Journal article (peer-reviewed)abstract The rare earths are known to have intriguing changes of the valence, depending on the chemical surrounding or geometry. Here, we aim at predicting the transition of valence when passing from the atomic divalent limit to the bulk trivalent limit. This transition is analyzed by addressing clusters of various size for selected rare-earth elements, i.e., Sm, Tb, and Tm, via a theoretical treatment that combines density functional theory with atomic multiplet theory. Our results show that Tm clusters change from pure divalent to pure trivalent at a size of six atoms, while Tb clusters are already divalent for two atoms and stay so until eight atoms and the bulk limit. Instead, Sm clusters are respectively purely divalent up to eight atoms. For larger Sm clusters, a transition to a trivalent configuration is expected and likely accompanied by a regime of mixed valence. The valence of all rare-earth clusters, as a function of size, is predicted from the interpolation of our calculated results. These predictions are argued to be best investigated by spectroscopic measurements. To ease experimental analysis, we provide theoretical spectra, based on dynamical mean-field theory in the Hubbard I approximation.
25.	Shick, A. B., et al. (author) Unified character of correlation effects in unconventional Pu-based superconductors and delta-Pu 2013 In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 87:2, s. 020505- Journal article (peer-reviewed)abstract Electronic structure calculations combining the local-density approximation with an exact diagonalization of the Anderson impurity model show an intermediate 5 f(5)-5 f(6)-valence ground state and delocalization of the 5 f(5) multiplet of the Pu atom 5f shell in PuCoIn5, PuCoGa5, and delta-Pu. The 5f local magnetic moment is compensated by a moment formed in the surrounding cloud of conduction electrons. For PuCoGa5 and delta-Pu the compensation is complete, and the Anderson impurity ground state is a singlet. For PuCoIn5 the compensation is partial, and the Pu ground state is magnetic. We suggest that the unconventional d-wave superconductivity is likely mediated by the 5 f-state antiferromagnetic fluctuations in PuCoIn5 and by valence fluctuations in PuCoGa5.
26.	Sotnikov, O. M., et al. (author) Certification of quantum states with hidden structure of their bitstrings 2022 In: NPJ QUANTUM INFORMATION. - : Springer Nature. - 2056-6387. ; 8:1 Journal article (peer-reviewed)abstract The rapid development of quantum computing technologies already made it possible to manipulate a collective state of several dozens of qubits, which poses a strong demand on efficient methods for characterization and verification of large-scale quantum states. Here, we propose a numerically cheap procedure to distinguish quantum states which is based on a limited number of projective measurements in at least two different bases and computing inter-scale dissimilarities of the resulting bit-string patterns via coarse-graining. The information one obtains through this procedure can be viewed as a 'hash function' of quantum state-a simple set of numbers which is specific for a concrete wave function and can be used for certification. We show that it is enough to characterize quantum states with different structure of entanglement, including the chaotic quantum states. Our approach can also be employed to detect phase transitions in quantum magnetic systems.
27.	Wessely and M. I. Katsnelson and A. Nilsson and A. Nikitin and H. Ogasawara and M. Odelius and B. Sanyal and O. Eriksson, O, et al. (author) Dynamical core-hole screening in the x-ray absorption spectra of hydrogenated carbon nanotubes and graphene} 2007 In: Physical Review B. ; 76, s. 161402- Journal article (peer-reviewed)
28.	Andersson, P H, et al. (author) Initial and final state effects in x-ray absorption spectra of transition metal oxides Journal article (peer-reviewed)
29.	Beutier, G., et al. (author) Band Filling Control of the Dzyaloshinskii-Moriya Interaction in Weakly Ferromagnetic Insulators 2017 In: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 119:16 Journal article (peer-reviewed)abstract We observe and explain theoretically a dramatic evolution of the Dzyaloshinskii-Moriya interaction (DMI) in the series of isostructural weak ferromagnets, MnCO3, FeBO3, CoCO3, and NiCO3. The sign of the interaction is encoded in the phase of the x-ray magnetic diffraction amplitude, observed through interference with resonant quadrupole scattering. We find very good quantitative agreement with first-principles electronic structure calculations, reproducing both sign and magnitude through the series, and propose a simplified "toy model" to explain the change in sign with 3d shell filling. The model gives insight into the evolution of the DMI in Mott and charge transfer insulators.
30.	Bleskov, I. D., et al. (author) Ab initio calculations of elastic properties of Ru1-xNixAl superalloys 2009 In: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 94:16 Journal article (peer-reviewed)abstract Ab initio total energy calculations based on the exact muffin-tin orbitals method, combined with the coherent potential approximation, have been used to study the thermodynamical and elastic properties of substitutional refractory Ru1-xNixAl alloys. We have found that the elastic constants C' and C11 exhibit pronounced peculiarities near the concentration of about 40 at. % Ni, which we ascribe to electronic topological transitions. Our suggestion is supported by the Fermi surface calculations in the whole concentration range. Results of our calculations show that one can design Ru-Ni-Al alloys substituting Ru by Ni (up to 40 at. %) with almost invariable elastic constants and reduced density.
31.	Boukhvalov D. W., Dobrovitski V. V., Katsnelson M. I. , Lichtenstein A. I., Harmon B. N., Kögerler P. (author) Electronic structure and exchange interactions in V15 magnetic molecules 2003 In: Journal of Applied Physics. ; , s. 7080- Conference paper (peer-reviewed)
32.	Boukhvalov D. W., Lichtenstein A. I., Dobrovitski V. V., Katsnelson M. I., Harmon B. N., Mazurenko V. V., Anisimov V. I. (author) Effect of local Coulomb interactions on the electronic structure and exchange interactions in Mn12 magnetic molecules 2002 In: Physical Review B. ; 65, s. 184435- Journal article (peer-reviewed)
33.	Bručas, R., et al. (author) Magnetic anisotropy and evolution of ground state domain structure in bcc Fe81Ni19/Co (001) superlattices Other publication (pop. science, debate, etc.)
34.	Brucas, R., et al. (author) Magnetic anisotropy and evolution of ground-state domain structures in bcc Fe81Ni19/Co(001) superlattices 2008 In: Physical Review B. Condensed Matter and Materials Physics. - : The American Physical Society. - 1098-0121 .- 1550-235X. ; 78:2, s. 024421- Journal article (peer-reviewed)abstract The magnetic anisotropy and evolution of striped magnetic domain structures in bcc Fe81Ni19/Co(001) superlattices with the total thickness ranging from 85 to 1370 nm has been studied by magneto-optical Kerr effect and magnetic force microscopy. At a thickness of about 85 nm [25 bilayers (BL)] the domains appear as stripe domains, typical for perpendicular anisotropy films, with the weak cubic anisotropy of the in-plane magnetization component stabilizing the stripe direction. The magnetic domain period strongly depends on the thickness of the superlattice. As the thickness increases, the equilibrium magnetization orients at oblique angles with respect to the film plane and continuously varies with the thickness from in-plane to out-of-plane. We first apply a simple phenomenological model which correctly predicts the transition from in-plane to out-of-plane magnetization as well as increasing domain period and saturation field with increasing BL number. The results indicate the presence of partial flux-closure domains at the film surface with the tilt angle continuously varying with the superlattice thickness. By solving a linearized Landau–Lifshitz equation together with Maxwell’s equations in magnetostatic approximation for samples consisting of up to 1000 individual layers, we calculate the spin-wave dispersion and determine the stability conditions for the saturated ferromagnetic state. From these results the dependence of the saturation field on the number of layers is inferred and agrees well with the experiment. The uniaxial bulk anisotropy is attributed to distortions along the c axis and the results further show evidence for the presence of an easy-plane interface anisotropy in these samples.
35.	Brucas, Rimantas, et al. (author) Magnetization and domain structure of bcc Fe81Ni19/Co (001) superlattices 2004 In: Phys. Rev. B. ; B 69 (6), s. 064411- Journal article (peer-reviewed)
36.	Bručas, R., et al. (author) Magnetization transitions and ground state domain phases in bcc Fe81Ni19/Co superlattices : On interface induced magnetic anisotropy Other publication (pop. science, debate, etc.)
37.	Cardias, R., et al. (author) The Bethe-Slater curve revisited; new insights from electronic structure theory 2017 In: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 7 Journal article (peer-reviewed)abstract The Bethe-Slater (BS) curve describes the relation between the exchange coupling and interatomic distance. Based on a simple argument of orbital overlaps, it successfully predicts the transition from antiferromagnetism to ferromagnetism, when traversing the 3d series. In a previous article [Phys. Rev. Lett. 116, 217202 (2016)] we reported that the dominant nearestneighbour (NN) interaction for 3d metals in the bcc structure indeed follows the BS curve, but the trends through the series showed a richer underlying physics than was initially assumed. The orbital decomposition of the inter-site exchange couplings revealed that various orbitals contribute to the exchange interactions in a highly non-trivial and sometimes competitive way. In this communication we perform a deeper analysis by comparing 3d metals in the bcc and fcc structures. We find that there is no coupling between the E-g orbitals of one atom and T-2g orbitals of its NNs, for both cubic phases. We demonstrate that these couplings are forbidden by symmetry and formulate a general rule allowing to predict when a similar situation is going to happen. In gamma-Fe, as in alpha-Fe, we find a strong competition in the symmetry-resolved orbital contributions and analyse the differences between the high-spin and low-spin solutions.
38.	Chioncel, L, et al. (author) Ab initio electronic structure calculations of correlated 2003 In: Phys. Rev. B. ; 67, s. 235106- Journal article (peer-reviewed)
39.	Chioncel, L., et al. (author) Ab initio electronic structure calculations of correlated systems : An EMTO-DMFT approach 2003 In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 67:23 Journal article (peer-reviewed)abstract We propose a self-consistent method for electronic structure calculations of correlated systems, which combines the local spin-density approximation (LSDA) and the dynamical mean field theory (DMFT). The LSDA part is based on the exact muffin-tin orbital approach, meanwhile the DMFT uses a perturbation scheme that includes the T matrix with fluctuation exchange approximation. The current LSDA+DMFT implementation fulfills both self-energy and charge self-consistency requirements. We present results on the electronic structure calculations for bulk 3d transition metals (Cr, Fe, and Ni) and for Fe/Cr magnetic multilayers. The latter demonstrates the importance of the correlation effects for the properties of magnetic heterostructures.
40.	Chioncel L., Katsnelson M. I., de Groot R. A., Lichtenstein A. I. (author) Nonquasiparticle states in the half-metallic ferromagnet NiMnSb 2003 In: Physical Review B. ; 68, s. 144425- Journal article (peer-reviewed)
41.	Costa, Marcio, et al. (author) Correlated electronic structure of Fe in bulk Cs and on a Cs surface 2013 In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 87:11, s. 115142- Journal article (peer-reviewed)abstract We have investigated the spectral properties of Fe impurities in a Cs host, for both surface and bulk systems, by means of a combination of density functional theory in the local density approximation and dynamical mean-field theory (LDA + DMFT). The effective impurity model arising in LDA + DMFT was solved via two different techniques, i.e., the Hubbard I approximation and the exact diagonalization. It is shown that noticeable differences can be seen in the unoccupied part of the spectrum for different positions of Fe atoms in the host, despite the fact that hybridization between Fe d-states and Cs is low. Our calculations show good agreement with the experimental photoemission spectra reported by Carbone et al. [Carbone, Veronese, Moras, Gardonio, Grazioli, Zhou, Rader, Varykhalov, Krull, Balashov, Mugarza, Gambardella, Lebegue, Eriksson, Katsnelson, and Lichtenstein, Phys. Rev. Lett. 104, 117601 (2010)].
42.	di Marco, Igor, et al. (author) An LDA+DMFT study of the orbital magnetism and total energy properties of the late transition metals: conserving and non-conserving approximations Other publication (other academic/artistic)
43.	Di Marco, I., et al. (author) Electron correlations in Mn(x)Ga(1–x)As as seen by resonant electron spectroscopy and dynamical mean field theory 2013 In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 4, s. 6-2645 Journal article (peer-reviewed)abstract After two decades since the discovery of ferromagnetism in manganese-doped gallium arsenide, its origin is still debated, and many doubts are related to the electronic structure. Here we report an experimental and theoretical study of the valence electron spectrum of manganese-doped gallium arsenide. The experimental data are obtained through the differences between off- and on-resonance photo emission data. The theoretical spectrum is calculated by means of a combination of density-functional theory in the local density approximation and dynamical mean field theory, using exact diagonalization as impurity solver. Theory is found to accurately reproduce measured data and illustrates the importance of correlation effects. Our results demonstrate that the manganese states extend over a broad range of energy, including the top of the valence band, and that no impurity band splits-off from the valence band edge, whereas the induced holes seem located primarily around the manganese impurity.
44.	Di Marco, Igor, et al. (author) Electron correlations in MnxGa1-xAs as seen by resonant electron spectroscopy and dynamical mean field theory 2013 In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723 .- 2041-1723. ; 4, s. 6- Journal article (peer-reviewed)abstract After two decades since the discovery of ferromagnetism in manganese-doped gallium arsenide, its origin is still debated, and many doubts are related to the electronic structure. Here we report an experimental and theoretical study of the valence electron spectrum of manganese-doped gallium arsenide. The experimental data are obtained through the differences between off- and on-resonance photo emission data. The theoretical spectrum is calculated by means of a combination of density-functional theory in the local density approximation and dynamical mean field theory, using exact diagonalization as impurity solver. Theory is found to accurately reproduce measured data and illustrates the importance of correlation effects. Our results demonstrate that the manganese states extend over a broad range of energy, including the top of the valence band, and that no impurity band splits-off from the valence band edge, whereas the induced holes seem located primarily around the manganese impurity.
45.	Di Marco, Igor, et al. (author) gamma-Mn at the border between weak and strong correlations 2009 In: European Physical Journal B. - : Springer Science and Business Media LLC. - 1434-6028 .- 1434-6036. ; 72:4, s. 473-478 Journal article (peer-reviewed)abstract We investigate the role of magnetic fluctuations in the spectral properties of paramagnetic gamma-Mn. Two methods are employed. The Local Density Approximation plus Dynamical Mean-Field Theory together with the numerically exact quantum Monte-Carlo solver is used as a reference for the spectral properties. Then the same scheme is used with the computationally less demanding perturbative spin-polarized fluctuation-exchange solver in combination with the Disordered Local Moment approach, and photoemission spectra are calculated within the one-step model. It is shown that the formation of local magnetic moments in gamma-Mn is very sensitive to the value of Hund's exchange parameter. Comparison with the experimental photoemission spectra demonstrates that gamma-Mn is a strongly correlated system, with the Hubbard band formation, which cannot be described by the perturbative approach. However, minor change of parameters would transform it into a weakly correlated system.
46.	Dobrovitski V. V., De Raedt H. A., Katsnelson M. I., Harmon B. N. (author) Quantum oscillations without quantum coherence 2003 In: Physical Review Letters. ; 90, s. 210401- Journal article (peer-reviewed)
47.	Dobrovitski V. V., Katsnelson M. I., Harmon B. N. (author) Length scale coupling for nonlinear dynamical problems in magnetism 2003 In: Physical Review Letters. ; 90, s. 067201- Journal article (peer-reviewed)
48.	Dobrovitski V. V., Katsnelson M. I., Harmon B. N. (author) Statistical coarse graining as an approach to multiscale problems in magnetism 2003 In: Journal of Applied Physics. ; , s. 6432- Conference paper (peer-reviewed)
49.	Gornostyrev Yu. N., Karkin I. N. , Katsnelson M. I., and Trefilov A. V. (author) Evolution of the atomic structure of metal clusters upon heating and cooling. Computer simulation of FCC metals 2003 In: Physics of Metals and Metallography. ; 96, s. 135- Journal article (peer-reviewed)
50.	Gornostyrev Yu. N., Katsnelson M. I., et al. (author) Kink nucleation in two-dimensional Frenkel-Kontorova model 2002 In: Physical Review E. ; 66, s. 027201- Journal article (peer-reviewed)

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