Related papers: Exchange interactions in two-state systems: rare e…
A simple theoretical model is developed to describe spin reorientation (SR) transitions in rare-earth orthoferrites and orthochromites RFeO3 and RCrO3. Within a ``single-doublet'' approach, the free energy includes anisotropy contributions…
Recent investigations of the two-dimensional spin-1/2 checkerboard lattice favor a valence bond crystal with long range quadrumer order [J.-B. Fouet et al., preprint cond-mat/0108070]. Starting from the limit of isolated quadrumers, we…
A pyrochlore lattice is considered where the average electron number of electrons per site is half--integer, concentrating on the case of exactly half an electron per site. Strong on-site repulsions are assumed, so that all sites are either…
Anisotropic intersite exchange interactions in frustrated rare-earth magnets are difficult to assess both theoretically and experimentally. Here, we propose an ab initio force-theorem framework combining the quasi-atomic Hubbard-I approach…
We study the spin ladder model with interactions between spins on neighboring rungs. The model Hamiltonian with the exact singlet ground state degenerated with ferromagnetic state is obtained. The singlet ground state wave function has a…
The competition between antiferromagnetic and spin-singlet ground states within quantum spin models and the 1/2-filled band Hubbard model has received intense scrutiny. Here we demonstrate a frustration-induced transition from N\'{e}el…
The structure of the low-energy electronic states in layered cobaltates is considered starting from the Mott insulating limit. We argue that the coherent part of the wave-functions and the Fermi-surface topology at low doping are strongly…
We study a model of the stripe state in strongly correlated systems consisting of an array of antiferromagnetic spin ladders, each with $n_{leg}$ legs, coupled to each other through the spin-exchange interaction to charged stripes in…
Contrary to the well known spin qubits, rare-earth qubits are characterized by a strong influence of crystal field due to large spin-orbit coupling. At low temperature and in the presence of resonance microwaves, it is the magnetic moment…
Motivated by a recent experiment [L. F. Livi, et al., Phys. Rev. Lett. 117, 220401(2016)], we study the ground-state properties of interacting fermions in a one-dimensional optical lattice clock with spin-orbit coupling. As the electronic…
We discuss the ground state of a pyrochlore lattice of threefold-orbitally-degenerate $S=1/2$ magnetic ions. We derive an effective spin-orbital Hamiltonian and show that the orbital degrees of freedom can modulate the spin exchange,…
The ground state ensemble of the highly frustrated pyrochlore-lattice antiferromagnet can be mapped to a coarse-grained ``polarization'' field satisfying a zero-divergence condition From this it follows that the correlations of this field,…
Here we present experimental evidence of the pseudo-doublet ground state of the non-Kramers compound SrTm2O4, based on specific heat, magnetic entropy and electron paramagnetic resonance. We demonstrate that the two crystallographic Tm3+…
There is a growing family of rare-earth kagome materials with dominant nearest-neighbor interactions and strong spin orbit coupling. The low symmetry of these materials makes theoretical description complicated, with six distinct…
Searching for the exotic interactions beyond the Standard Model of particle physics may solve some of the current puzzles in physics. Here the authors experimentally explore a spin- and velocity-dependent exotic interaction between the…
In many transition metal compounds, in particular those containing Fe^{2+} and Co^{3+}, there occur spin-state transitions between low-spin and high-spin (or intermediate-spin) states. We show that typical interactions between similar…
We study magnetism in simple models for rare earth quasicrystals by means of a two-step theoretical approach. First, we compute RKKY interactions from a tight-binding Hamiltonian defined on a two-dimensional quasiperiodic tiling. Second, we…
We consider a system of three weakly coupled Bose-Einstein condensates and two atomic quantum dots embedded in the barriers between the condensates. Each dot is coupled to two neighboring condensates by optical transitions and can be…
We explore the potential experimental realization of the mixed-spin Kitaev model in materials such as Zr$_{0.5}$Ru$_{0.5}$Cl$_3$, where spin-1/2 and spin-3/2 ions occupy distinct sublattices of a honeycomb lattice. By developing a…
The spin-1/2 Heisenberg model on the pyrochlore lattice is an iconic frustrated three-dimensional spin system with a rich phase diagram. Besides hosting several ordered phases, the model is debated to possess a spin-liquid ground state when…