In this work we examine critically the electronic structure of rare-earth elements by use so-called Hubbard I approximation. From theoretical side all measured features both occupied and unoccupied states are reproduced, without significant deviations between observations theory. We also cohesive properties like equilibrium volume bulk modulus, where find, in general, a good agreement theory measurements. addition, have reproduced spin orbital moments these as they reflected from...

Magnetoelasticity plays a crucial role in numerous magnetic phenomena, including magnetocalorics, magnon excitation via acoustic waves, and ultrafast demagnetization, or the Einstein–de Haas effect. Despite long-standing discussion on anisotropy-mediated magnetoelastic interactions of relativistic origin, exchange-mediated parameters within an atomistic framework have only recently begun to be investigated. As result, many their behaviors values for real materials remain poorly understood....

Quantum magnonics is an emerging research field, with great potential for applications in magnon based hybrid systems and quantum information processing. correlation, such as entanglement, a central resource many protocols that naturally comes about any study toward technologies. This applies also to magnonics. Here, we investigate antiferromagnets which sublattices ferromagnetic interactions can have two different modes, show how this may lead experimentally detectable bipartite continuous...

Abstract Despite decades of research, the role lattice and its coupling to magnetisation during ultrafast demagnetisation processes is still not fully understood. Here we report on studies both explicit implicit effects laser induced bcc Fe fcc Co. We do this using atomistic spin- dynamics simulations following a heat-conserving three-temperature model. show that type Langevin-based simulation able reproduce observed trends magnetization Co Fe. The parameters used in our models are all...

The ground-state electronic and magnetic properties of small silver clusters ${\mathrm{Ag}}_{n}$ $(2\ensuremath{\leqslant}n\ensuremath{\leqslant}22)$ have been studied using a linear combination atomic Gaussian-type orbitals within the density functional theory. results show that atoms, which are diamagnetic in bulk environment, can be when they grouped together clusters. ${\mathrm{Ag}}_{13}$ cluster with icosahedral symmetry has highest moment per atom among studied. reduced coordination...

The static response properties and the structural stability of silver clusters in size range $1\ensuremath{\le}n\ensuremath{\le}23$ have been studied using a linear combination atomic Gaussian-type orbitals within density functional theory finite field approach. Kohn-Sham equations solved conjunction with generalized gradient approximation (GGA) exchange-correlation functional. A proof that basis set GGA calculation satisfies Hellmann-Feynman theorem is also included Appendix. calculated...

In recent years, there has been an intense interest in understanding the microscopic mechanism of thermally induced magnetization switching driven by a femtosecond laser pulse. Most effort dedicated to periodic crystalline structures while amorphous counterparts have less studied. By using multiscale approach, i.e. first-principles density functional theory combined with atomistic spin dynamics, we report here on very intricate structural and magnetic nature Gd-Fe alloys for wide range Gd Fe...

An essential property of magnetic devices is the relaxation rate in switching which strongly depends on energy dissipation. This described by Landau-Lifshitz-Gilbert equation and well known damping parameter, has been shown to be reproduced from quantum mechanical calculations. Recently importance inertia phenomena have discussed for magnetisation dynamics. counterpart well-known Newtonian mechanics, represents a research field that so far received only limited attention. We present...

We propose a new efficient permanent magnet, SmCoNiFe3, that is breakthrough development of the well-known SmCo5 prototype. More modern neodymium magnets Nd-Fe-B type have an advantage over because their greater maximum energy products due to iron-rich stoichiometry. Our however, removes most this disadvantage while preserving its superior high-temperature efficiency magnets.

The Dzyaloshinskii-Moriya (DM) interaction, as well symmetric anisotropic exchange, are important ingredients for stabilizing topologically nontrivial magnetic textures, such as, e.g., skyrmions, merons, and hopfions. These types of textures currently in focus from a fundamental science perspective they also discussed the context future spintronics information technology. While theoretical understanding Heisenberg exchange interactions is developed, it still challenge to access, first...

<a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:msub><a:mi>YMn</a:mi><a:mn>6</a:mn></a:msub><a:msub><a:mi>Sn</a:mi><a:mn>6</a:mn></a:msub></a:mrow></a:math> consists of two types Mn-based kagome planes stacked along the <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mi>c</b:mi></b:math>-axis having a complex magnetic interaction. We report spin reconstruction in <c:math...

We study the influence of non-local damping on magnon properties Fe, Co, Ni and Fe$_{1-x}$Co$_{x}$ ($x=30\%,50\%$) alloys. The Gilbert parameter is typically considered as a local scalar both in experiment theoretical modelling. However, recent works have revealed that quantity allows for energy dissipation between atomic sites. With parameters calculated from state-of-the-art real-space electronic structure method, lifetimes are evaluated spin dynamics linear response, where good agreement...

Femtosecond laser pulses can be used to induce ultrafast changes of the magnetization in magnetic materials. Several microscopic mechanisms have been proposed explain these observations, including transport ultrashort spin-polarized hot-electrons (SPHE). However, currently such spin currents are only poorly characterized due measurement requirements for element and time resolution. Here, using time- element-resolved X-ray circular dichroism alongside atomistic spin-dynamics simulations, we...

Traditional magnetic phase diagram represents a transition between the ferromagnetic and paramagnetic states of material under influence varied temperature, field, pressure. So far, has been considered predominantly as single type magnetization texture extending macroscopically in bulk crystal, existing ground state determined by interactions localized moments arranged lattice. Here, it is demonstrated that an unconventional order composed vertically correlated planar sub-domains occurs...

Among the quasi-two-dimensional van der Waals magnetic systems, <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:msub><a:mi mathvariant="normal">Fe</a:mi><a:mn>4</a:mn></a:msub><a:mi>Ge</a:mi><a:msub><a:mi mathvariant="normal">Te</a:mi><a:mn>2</a:mn></a:msub></a:mrow></a:math> makes a profound impact due to its near-room-temperature ferromagnetic behavior and complex magnetothermal phase diagram exhibiting multiple transformations, as observed from magnetization...

In this work, we present electronic and magnetic properties of CaMnO3 (CMO) as obtained from ab initio calculations. We identify the preferable order by means density functional theory plus Hubbard U calculations extract effective exchange parameters (Jij's) using force theorem. find that effects geometrical relaxation at surface well change crystal field are very strong able to influence lower energy configuration. particular, our analysis reveals interaction between Mn atoms belonging...

An essential property of magnetic devices is the relaxation rate in switching which depends strongly on damping magnetisation dynamics. It was recently measured that texture and, consequently, a non-local quantity. The enters Landau-Lifshitz-Gilbert equation as phenomenological Gilbert parameter $α$, does not, straight forward formulation, account for non-locality. Efforts were spent to obtain from first principles magnons wave vector $\mathbf{q}$. However, best our knowledge, there no...

Multireservoir models are widely used for modeling and interpreting ultrafast magnetization dynamics. Here we introduce an alternative formulation to existing three-temperature the treatment of spin, electron, lattice temperatures in dynamics simulations. In contrast most calculations energy transfer between reservoirs these types simulations, heat distribution spin subsystems is evaluated during simulation instead being calculated a priori. The model applied investigate demagnetization...

Abstract Using ab initio density functional theory with static mean-field correlations, we calculate the Heisenberg and Dzyaloshinskii-Moriya interactions (DMI) for an atomistic spin Hamiltonian lacunar spinel, GaV 4 S 8 . The parameters describing these are used in dynamics micromagnetic simulations. magnetic properties of spinel , a material well-known from experiment to host skyrmions Néel character, simulated calculated parameters. contribution energy is sum two Lifshitz invariants,...

The magnetocaloric effect (MCE) in one-dimensional (1D) magnetic nanostructures is optimized for a specific value of the field ${H}^{*}$ when applied perpendicularly to longitudinal direction system. Our results reveal that corresponds saturation field, slightly above transition from magnetically stable dipolar-coupled configuration an unstable one. This MCE-optimizing explicitly depends on characteristic parameters system, namely, magnetization (${M}_{S}$) and anisotropy constant ($K$):...

We show for a simple noncollinear configuration of the atomistic spins (in particular, where one spin is rotated by finite angle in ferromagnetic background) that pairwise energy variation computed terms multiple-scattering formalism cannot be fully mapped onto bilinear Heisenberg model even absence spin-orbit coupling. The non-Heisenberg induced spin-polarized host appear leading orders expansion infinitesimal variations. However, an ${E}_{g}\ensuremath{-}{T}_{2g}$ symmetry analysis based...

Heusler alloys have been intensively studied due to the wide variety of properties that they exhibit. One these is particular interest for technological applications, i.e., fact some are half-metallic. In following, a systematic study magnetic three different families ${\mathrm{Co}}_{2}\mathrm{Mn}\mathrm{Z},{\text{Co}}_{2}\text{Fe}\text{Z}$, and ${\mathrm{Mn}}_{2}\mathrm{V}\mathrm{Z}$ with...

Materials with strong spin-orbit interactions are presently a main target in the search for systems novel magnetic properties. Magnetic anisotropies can be very large such compounds, ranging from strongly frustrated Kitaev exchange and associated spin-liquid states honeycomb iridates to robust antisymmetric couplings square-lattice ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$. Here we predict ab initio quantum chemistry calculations that another highly unusual regime is realized pyrochlore iridium...

Originating from image recognition, methods of machine learning allow for effective feature extraction and dimensionality reduction in multidimensional datasets, thereby providing an extraordinary tool to deal with classical quantum models many-body physics. In this study, we employ a specific unsupervised technique -- self-organizing maps create low-dimensional representation microscopic states, relevant macroscopic phase identification detecting transitions. We explore the properties spin...