Related papers: Geometry induced phase transitions in magnetic sph…
Above the saturation field, geometrically frustrated quantum antiferromagnets have dispersionless low-energy branches of excitations corresponding to localized spin-flip modes. Transition into a partially magnetized state occurs via…
Quantum phase transitions between the magnetically ordered and disordered states are studied for the two-dimensional antiferromagnetic quantum spin systems with ladder, plaquette, and mixed-spin structures. Starting with properly chosen…
Graphene nanoflakes are interesting because electrons are naturally confined in these quasi-zero-dimensional structures, whereas confinement in bulk graphene would require a band gap. Vacancies inside the graphene lattice lead to localized…
The magnetic relaxation of ferromagnetic powders has been studied for many years, largely due to its importance to recording technologies. However, only recently have experiments been performed that resolve the magnetic state of individual…
Magnetic vortices in soft ferromagnetic nano-disks have been extensively studied for at least several decades both for their fundamental (as a "live" macroscopic realization of a field theory model of an elementary particle) as well as…
In the majority of magnetic systems the surface is required to order at the same temperature as the bulk. In the present study, we report a distinct and unexpected surface magnetic phase transition, uniquely at a lower temperature than the…
In quantum many-body systems with local interactions, the effects of boundary conditions are considered to be negligible, at least for sufficiently large systems. Here we show an example of the opposite. We consider a spin chain with two…
We analyze magnetic phases of monolayers of transition metal dichalcogenides that are two-valley materials with electron-electron interactions. The exchange inter-valley scattering makes two-valley systems less stable to the spin…
In magnetically-doped quantum dots changing the carrier occupancy, from open to closed shells, leads to qualitatively different forms of carrier-mediated magnetic ordering. While it is common to study such nanoscale magnets within a mean…
We demonstrate magnetic switching between two $360^\circ$ domain wall vortex states in cobalt nanorings, which are candidate magnetic states for robust and low power MRAM devices. These $360^\circ$ domain wall (DW) or "twisted onion" states…
Ab-initio results for structural and electronic properties of NaCl-type FeN are presented in a framework of plane-wave and ultrasoft pseudopotentials. Competition among different magnetic ordering is examined. We find the ferromagnetic…
Switching of the direction of the magnetic moment in a nanomagnet is studied within a modified Slonczewski's model that permits torsional oscillations of the magnet. We show that the latter may inhibit or assist the magnetization switching,…
In structurally disordered ferromagnets the weak random dipole-dipole exchange may transform the polydomain state into a spin-glass one. To some extent the properties of such phase in disordered isotropic ferromagnet can be qualitatively…
We theoretically predict a nonequilibrium phase transition in quantum spin systems induced by a laser, which provides a purely quantum-mechanical way of coherently controlling magnetization. Namely, when a circularly polarized laser is…
Thermodynamics of layered Ising magnet with the infinite-range ferromagnetic intralayer interaction and random exchange between nearest layers is considered. The case of zero average interlayer exchange is studied in detail. The…
By combining first-principles electronic-structure calculations with the model Hamiltonian approach, we systematically study the magnetic properties of sodium superoxide (NaO2), originating from interacting superoxide molecules. We show…
The ground state of colloidal magnetic particles in a modulated channel are investigated as function of the tilt angle of an applied magnetic field. The particles are confined by a parabolic potential in the transversal direction while in…
Finite-temperature micromagnetics simulations are employed to study the magnetization-switching dynamics driven by a field applied at an angle to the long axis of an iron nanopillar. A bi-modal distribution in the switching times is…
Quenched thermodynamic states of an amorphous ferromagnet are studied. The magnet is a countable collection of point particles chaotically distributed over $\mathbb{R}^d$, $d\geq 2$. Each particle bears a real-valued spin with symmetric a…
We explore how the quantum geometric properties of the Bloch wave function, characterized by the Hilbert-Schmidt quantum distance, impact magnetic phases in solid-state systems. To this end, we investigate the spin susceptibility within the…