Related papers: Magnetic softness in iron-based superconductors
Despite of the importance of magnetism in possible relation to other key properties in iron-based superconductors, its understanding is still far from complete especially for FeSe systems. On one hand, the origin of the absence of magnetic…
We report on the structural and magnetic properties of single and double atomic layers of Mn on a clean and unreconstructed Nb(110) substrate. Low-temperature scanning tunneling spectroscopy measurements reveal a proximity-induced…
We propose a simple model of charge and/or magnetic order formation in systems containing both localized and itinerant electrons coupled by the on-site, spin-dependent interaction that represents Coulomb repulsion and Hund's rule (a…
The most powerful magnets for high temperature applications are Sm-Co-based alloys with a microstructure that combines magnetically soft and hard regions. The microstructure consists of a dense domain-wall-pinning network that endows the…
We present a theory of the spin Hall magnetoresistance of metals in contact with magnetic insulators. We express the spin-mixing conductances, which govern the phenomenology of the effect, in terms of the microscopic parameters of the…
Motivated by the premise that superconductivity in iron-based superconductors is unconventional and mediated by spin fluctuations, an intense research effort has been focused on characterizing the spin excitation spectrum in the…
Motivated by the close correlation between transition temperature ($T_c$) and the tetrahedral bond angle of the As-Fe-As layer observed in the iron-based superconductors, we study the interplay between spin and orbital physics of an…
This thesis investigates the magnetic, spectral, and transport properties of strongly correlated electronic systems, with a primary focus on the Hubbard model and its extensions relevant for real materials. Within the dynamical mean-field…
Developing a comprehensive magnetic theory for correlated itinerant magnets poses challenges due to the difficulty in reconciling both local moments and itinerant electrons. In this work, we investigate the microscopic process of magnetic…
Rhombohedral graphene multilayers host various broken-symmetry metallic phases as well as superconductors whose pairing mechanism and order parameter symmetry remain unsettled. Strikingly, experiments have revealed prominent new…
An effective quantum parameter is obtained for the band ferromagnet in terms of orbital degeneracy and Hund's coupling. This quantum parameter determines, in analogy with 1/N for the generalized Hubbard model and 1/S for quantum spin…
We demonstrate that strong inter-orbital interaction is very efficient to achieve superconductivity due to magnetic fluctuations in the iron pnictides. Fermi surface states that are coupled by the antiferromagnetic wave vector are often of…
We analyze the origin of superconductivity in a ferromagnetically ordered state of multi-layer graphene systems placed in proximity to WSe$_2$. We model these materials by a two-valley system of interacting fermions with small pockets and…
We present first-principles calculations of the coupling of quasiparticles to spin fluctuations in iron selenide and discuss which types of superconducting instabilities this coupling gives rise to. We find that strong antiferromagnetic…
We present an exact ground state solution of a one-dimensional electronic model for transition-metal oxides in the strong coupling limit. The model contains doubly degenerated orbit for itinerant electrons and the Hund coupling between the…
Superparamagnetic nanoparticles containing hundreds and thousands of coupled electron spins are on the boundary between classical and quantum behavior, and demonstrate features which are typical for paramagnetic spins and absent in…
The recent observation of an inflection point in the temperature dependence of the in-plane magnetic field dependence (lambda_ab) is investigated within a two-band model with coupled order parameters of different symmetries. While the…
The influence of hyperfine coupling to nuclear spins and of their quadrupolar splitting on the induced moment order in singlet ground state magnets is investigated. The latter are found among non-Kramers f electron compounds. Without…
In the iron pnictide superconductors, theoretical calculations have consistently shown enhancements of the static magnetic susceptibility at both the stripe-type antiferromagnetic (AFM) and in-plane ferromagnetic (FM) wavevectors. However,…
Ferrites, magnetic materials primarily composed of iron oxides, exhibit diverse magnetic behaviors, including diamagnetism, paramagnetism, ferromagnetism, antiferromagnetism, ferrimagnetism, and superparamagnetism. This paper explores the…