arXiv subjects

Murod Mirzhalilov

Publications and source records attributed to Murod Mirzhalilov.

5 recordsLinked to original sources

arXiv2026

Domain-wall drift in a ferrimagnet induced by a linearly oscillating in-plane magnetic field

We investigate ferrimagnetic domain-wall dynamics under linearly oscillating in-plane magnetic fields. Starting from a ferrimagnetic Lagrangian that retains the field-dependent contribution to the kinetic energy, we derive collective-coordinate equations for the domain-wall position and azimuthal angle. This formulation makes explicit the field-induced inertial terms, including Coriolis-, Euler-, and centrifugal-like contributions, and clarifies how they couple translational and azimuthal dynamics. For an oscillating in-plane field supplemented by a weak static out-of-plane bias field, we show that periodic switching of the wall angle can be rectified into a finite average domain-wall velocity. At low drive frequencies, where the wall angle follows the oscillating field, the induced drift is proportional to the drive frequency rather than the field amplitude, while above a cutoff frequency the wall angle can no longer follow the drive and the average motion is suppressed. Micromagnetic simulations confirm the analytical predictions and demonstrate that the magnitude and direction of the drift can be tuned by the net spin density. These results identify linearly oscillating fields as a mechanism for frequency-controlled domain-wall motion in ferrimagnets and highlight the role of inertial spin dynamics near magnetic compensation.

cond-mat.str-el↗

arXiv2026

Understanding insulating ferromagnetism in LaCoO3 films under tensile strain

LaCoO3 thin films grown under epitaxial tensile strain exhibit a robust ferromagnetic insulating state that is absent in the bulk. Despite many studies, both experimental and computational, the microscopic origin of this phenomenon is not well understood. In this work, density functional theory calculations are used to systematically investigate the magnetic ground state of stoichiometric LaCoO3 under epitaxial strain equivalent to that imposed by a SrTiO3 substrate. The results identify a ferromagnetic insulating ground state characterized by a unique ordered array of high-spin (HS) and low-spin (LS) Co3+ ions. The spin state ordering is best described as 2 x 2 columns that consist of alternating HS and LS Co3+ ions, separated by planes of LS Co3+ ions. This leads to HS-LS-LS repeating sequence of Co3+ ions in both pseudocubic [100] and [010] directions. Analysis of the electronic structure confirms the presence of an insulating gap. Evaluation of the superexchange interactions reveal ferromagnetic interactions between HS Co3+ ions via 90 degree paths, and antiferromagnetic interactions via 180 degree paths, both of which are facilitated by empty sigma* (eg) orbitals on the diamagnetic LS Co3+ ions. The strength and number of 90 degree ferromagnetic interactions are sufficient to overcome the competing 180 degree antiferromagnetic interactions stabilizing a ferromagnetic insulating state.

cond-mat.mtrl-sci↗

arXiv2025

Enhancement of Curie Temperature in Ferromagnetic Insulator-Topological Insulator Heterostructures

We theoretically analyze the topological insulator (TI) surface state mediated interactions between local moments in a proximate 2D ferromagnetic insulator (FMI) motivated by recent experiments that show a significant increase in the Curie temperature Tc of FMI-TI heterostructures. Such interactions have been investigated earlier with a focus on dilute magnetic dopants in TIs. Our problem involves a dense set of moments for which we find that the short range Bloembergen-Rowland interaction, arising from virtual particle-hole transitions between the valence and conduction bands, dominates over the oscillatory Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction. We show that the Tc enhancement is proportional to the Van Vleck susceptibility and that the spin-momentum locking of surface states leads to out-of-plane ferromagnetic order in the FMI. We investigate how the hybridization between top and bottom surfaces in a thin TI film impacts Tc enhancement, and show how our results can help understand recent experiments on atomically thin Cr2Te3-(Bi,Sb)2Te3.

cond-mat.str-el↗

arXiv2025

Enhanced Ferromagnetism in Monolayer Cr2Te3 via Topological Insulator Coupling

Exchange-coupled interfaces are pivotal in exploiting two-dimensional (2D) ferromagnetism. Due to the extraordinary correlations among charge, spin, orbital and lattice degrees of freedom, layered magnetic transition metal chalcogenides (TMCs) bode well for exotic topological phenomena. Here we report the realization of wafer-scale Cr2Te3 down to monolayer (ML) on insulating SrTiO3(111) and/or Al2O3(001) substrates using molecular beam epitaxy. Robust ferromagnetism persists in the 2D limit. In particular, the Curie temperature TC of 2 ML Cr2Te3 increases from 100 K to ~ 120 K when proximitized to topological insulator (TI) (Bi,Sb)2Te3, with substantially boosted magnetization as observed via polarized neutron reflectometry. Our experiments and theory strongly indicate that the Bloembergen-Rowland interaction is likely universal underlying TC enhancement in TI-coupled magnetic heterostructures. The topological-surface-enhanced magnetism in 2D TMC enables further exchange coupling physics and quantum hybrid studies, including paving the way to realize interface-modulated topological electronics.

cond-mat.mtrl-sci↗

arXiv2020

Perpendicular space accounting of localized states in a quasicrystal

Quasicrystals can be described as projections of sections of higher dimensional periodic lattices into real space. The image of the lattice points in the projected out dimensions, called the perpendicular space, carries valuable information about the local structure of the real space lattice. In this paper, we show that perpendicular space projection can be used to analyze the elementary excitations of a quasicrystal. In particular, we consider the vertex tight binding model on the two dimensional Penrose lattice and investigate the properties of strictly localized states using perpendicular space images. Our method reproduces the previously reported frequencies for the six types of localized states in this model. We also calculate the overlaps between different localized states and show that the number of type-5 and type-6 localized states which are independent from the four other types is a factor of golden ratio $τ=(1+\sqrt{5})/2$ higher than previously reported values. Two orientations of the same type-5 or type-6 which are supported around the same site are shown to be linearly dependent with the addition of other types. We also show through exhaustion of all lattice sites in perpendicular space that any point in the Penrose lattice is either in the support of at least one localized state or is forbidden by local geometry to host a strictly localized state.

cond-mat.mes-hall↗