Related papers: Ashkin-Teller model with antiferromagnetic four-sp…
Under the second-order degenerate perturbation theory, we show that the physics of $N$ particles with arbitrary spin confined in a one dimensional trap in the strongly interacting regime can be described by super-exchange interaction. An…
We develop the field theory of antiferromagnets to layered structures on BCT crystal lattices with nearest-neibour and next-nearest-neighbour ferro- and/or antiferromagnetic interactions. For this aim the field theoretical counterpart of a…
We present a simple model that supports superconductive and antiferromagnetic ordering. The model consists of a system of electrons on a simple cubic lattice that move by tunnel effect and interact via antiferromagnetic Ising spin couplings…
Non-dyadic higher-order interactions affect collective behavior in various networked dynamical systems. Here we discuss the properties of a novel Ising model with higher-order interactions and characterize its phase transitions between the…
Critical and compensation properties of a mixed spin-1 and spin-3/2 Ising ferrimagnet on a square lattice are investigated by standard and histogram Monte Carlo simulations. The critical temperature is studied as a function of a single-ion…
We introduce a solvable quantum antiferromagnetic model. The model, with Ising spins in a transverse field, has infinite range antiferromagnetic interactions with random fields on each site, following an arbitrary distribution. As is…
In the last decades multifaceted manifestations of the breakdown of the self-consistent perturbation theory have been identified for the many-electron problem. Yet, the investigations have been so far mostly limited to paramagnetic states,…
In systems with many local degrees of freedom, high-symmetry points in the phase diagram can provide an important starting point for the investigation of their properties throughout the phase diagram. In systems with both spin and orbital…
The one-dimensional transverse Ising model is a paradigmatic example of quantum criticality. In spin-orbit coupled systems, however, effective Ising interactions arise alongside bond-dependent couplings such as Kitaev ($K$) and $\Gamma$…
We study a generalization of the well-known classical two-dimensional square lattice compass model of XY spins (sometimes referred to as the 90$^\circ$ compass model), which interpolates between the XY model and the compass model. Our model…
We investigate the Heisenberg model on a decorated square (Fisher) lattice in the presence of first-neighbor $J_{1}$, second-neighbor $J_{2}$, and third-neighbor $J_{3}$ exchange couplings, with antiferromagnetic $J_{1}$. The classical…
In this work, we employed Monte Carlo simulations to study the Ising, $XY$, and Heisenberg models on a simple cubic lattice, where the system models evolve toward the steady state under the influence of competition between one- and two-spin…
The ground state of the multiple-spin exchange model with up to the six-spin exchange interactions on a triangular lattice in the magnetic field is investigated within the mean-field approximation. By comparing the phase diagrams of systems…
Electronic nematicity is rarely observed as an isolated instability of a correlated electron system. Instead, in iron pnictides and in certain cuprates and heavy-fermion materials, nematicity is intertwined with an underlying spin-stripe or…
A theory is proposed to describe the competition among antiferromagnetism (AF), spin glass (SG) and Kondo effect. The model describes two Kondo sublattices with an intrasite Kondo interaction strength $J_{K}$ and a random Gaussian…
The study of interacting topological bands with a tunable bandwidth offers a unique platform to study the interplay of intertwined orders and emergent non-electronic excitations. Here we design a time-reversal symmetric and…
The multi-layer $S={1\over 2}$ square lattice Heisenberg antiferromagnet with up to 6 layers is studied via various series expansions. For the systems with an odd number of coupled planes, the ground-state energy, staggered magnetization,…
The spin-$\frac{1}{2}$ delta-chain (sawtooth chain) with antiferromagnetic Heisenberg basal chain and Ising apical-basal interactions is studied. The basal-apical interactions involve the bond alternation. The limiting cases of the model…
Macroscopic quantum coherence and spin-phase interference are studied between excited levels in single-domain ferromagnetic particles in a magnetic field along the hard anisotropy axis. The system has the general structure of…
Achieving long-range ferrimagnetic order in purely organic systems remains a major challenge in molecular magnetism. Here we report the synthesis and characterization of heterospin-coupling motifs, formed by covalently linking spin-1/2 and…