相关论文: The existence of a stable noncollinear phase in a …
It is well-known that in thin ferromagnetic film with a net magnetization perpendicular to the film the collinear arrangement of spins is unstable in an in-plane field $H$ smaller than its saturation value $H_c$. Existence of a stripe phase…
We present a new approach to study the magnetic phase stability of magnetic overlayers on nonmagnetic substrates. The exchange integrals among magnetic atoms in the overlayer are estimated in the framework of the adiabatic approximation and…
We investigate the stability of the collinear ferromagnetic state in kinetic exchange models for (III,Mn)V semiconductors with randomly distributed Mn ions >. Our results suggest that {\em noncollinear ferromagnetism} is commom to these…
The magnetic force theorem provides convenient ways to study exchange interactions in magnetic systems. However, it is well known that short range interactions in itinerant magnetic systems are poorly described with the conventional use of…
We consider the magnetic phase diagram of the two-dimensional Hubbard model on a square lattice. We take into account both spiral and collinear incommensurate magnetic states. The possibility of phase separation of spiral magnetic phases is…
The one-dimensional spin-1/2 $XXZ$ model in a mixed transverse and longitudinal magnetic field is studied. Using the specially developed version of the mean-field approximation the order-disorder transition induced by the magnetic field is…
A nonlinear model of the scalar field with a coupling between the field and its gradient is developed. It is shown, that such model is suitable for the description of phase transition accompanied by formation of spatial inhomogeneous…
A novel approach for studying phase transitions in systems with quantum degrees of freedom is discussed. Starting from the microscopic hamiltonian of a quantum model, we first derive a set of exact differential equations for the free energy…
The two dimensional Heisenberg antiferromagnet on the square lattice with nearest (J1) and next-nearest (J2) neighbor couplings is investigated in the strong frustration regime (J2/J1>1/2). A new effective field theory describing the long…
By means of ab initio calculations based on the density functional theory we investigated magnetic phase diagram of ordered FePd$_3$ alloy as a function of external pressure. Considering several magnetic configurations we concluded that the…
Heusler compounds constitute a large family of intermetallic materials notable for their wide variety of properties such as magnetism, multi-ferroicity, nontrivial band topology, superconductivity and so on. Among their magnetic properties…
We derive an effective field theory for a noncollinear altermagnet and magnons on top of the noncollinear ground state from an altermagnetic Heisenberg model. We obtain the ground-state phase diagram, revealing a noncollinear phase and four…
There are at least two different putative steady state solutions for current across noncollinear magnetic multilayers; one has a discontinuity in the spin current at the interface the other is continuous. We compare the resistance of the…
We study the quantum phase diagram of the Heisenberg planar antiferromagnet with a subset of four-spin ring exchange interactions, using the recently proposed heirarchical mean-field approach. By identifying relevant degrees of freedom, we…
Classical Heisenberg antiferromagnets with uniaxial exchange anisotropy and a cubic anisotropy term in a field on simple cubic lattices are studied with the help of ground state considerations and extensive Monte Carlo simulations.…
The stability and dynamics of a free magnetic polaron are studied by Monte Carlo simulation of a classical two-dimensional Heisenberg model coupled to a single electron. We compare our results to the earlier mean-field analysis of the…
Motivated by the discovery of spiral and modulated collinear phases in several magnetic materials, we investigate the magnetic properties of Heisenberg spin S=1/2 antiferromagnets in 2 and 3 dimensions, with frustration arising from…
Competing magnetically ordered structures in polymerized orthorhombic A1C60 are studied. A mean-field theory for the equilibrium phases is developed using an Ising model and a classical Heisenberg model to describe the competition between…
The nonequilibrium dynamic phase transition in ferromagnetic systems is reviewed. Very recent results of dynamic transition in kinetic Ising model and that in Heisenberg ferromagnet is discussed.
Motivated by the importance of non-collinear and non-coplanar magnetic phases in determining various electrical properties of magnetic materials, we investigate the phase diagrams of the extended Hubbard model on anisotropic triangular…