Related papers: Frustrated two dimensional quantum magnets
Geometric frustration lies at the heart of many unconventional quantum phases in strongly interacting electron systems. Here, we analytically determine the ground state magnetization of the half-filled Hubbard model on frustrated geometries…
We report on classical Monte Carlo study of phase transitions and critical behavior of a 2D spin-pseudospin model describing a dilute magnet with competing charge and spin interactions. The static critical exponents of the specific heat and…
We report on recent results for strongly frustrated quantum $J_1$-$J_2$ antiferromagnets in dimensionality d=1,2,3 obtained by the coupled cluster method (CCM). We demonstrate that the CCM in high orders of approximation allows us to…
The very interesting magnetic properties of frustrated magnetic molecules are often hardly accessible due to the prohibitive size of the related Hilbert spaces. The finite-temperature Lanczos method is able to treat spin systems for Hilbert…
The J1-J2 square lattice Heisenberg model with spin S=1/2 has three phases with long-range magnetic order and two unconventionally ordered phases depending on the ratio of exchange constants. It describes a number of recently found layered…
We study the effects of quantum fluctuations in magnetic properties of quantum frustrated ferromagnets in a magnetic field. It is shown that a non-classical phase or a phase separation appears due to quantum fluctuations below the…
In this Letter we report how thermodynamic properties of a giant frustrated magnetic Keplerate molecule of N=30 spins s=1/2 can be evaluated with the help of the highly accurate finite-temperature Lanczos method. The comparison to…
Thermodynamic properties of cubic Heisenberg ferromagnets with competing exchange interactions are considered near the frustration point where the coefficient $D$ in the spin-wave spectrum $E_{\mathbf{k}}\sim D k^{2}$ vanishes. Within the…
The accurate determination of magnetic phase transitions in electronic systems is an important task of solid state theory. While numerically exact results are readily available for model systems such as the half-filled 3D Hubbard model, the…
The frustration properties of the Ising model on a one-dimensional monoatomic equidistant lattice are investigated taking into account the exchange interactions of atomic spins at the sites of the first (nearest), second (next-nearest) and…
Frustration in magnetic materials arising from competing exchange interactions can prevent the system from adopting long-range magnetic order and can instead lead to a diverse range of novel quantum and topological states with exotic…
We study the zero-temperature phase diagram of the frustrated square-lattice S=1/2 antiferromagnet in an external magnetic field numerically with the Lanczos algorithm. For strong frustration, we find disordered phases at high (and low)…
Some magnetic systems display a shift in the center of their magnetic hysteresis loop away from zero field, a phenomenon termed exchange bias. Despite the extensive use of the exchange bias effect, particularly in magnetic multilayers, for…
The Cairo pentagonal lattice, consisting of an irregular pentagonal tiling of magnetic ions on two inequivalent sites (3- and 4-co-ordinated ones), represents a fascinating example for studying geometric frustration effects in…
Square-lattice systems offer a direct route for realizing 2D quantum magnetism with frustration induced by competing interactions. In this work, the square-lattice materials YbBi2IO4 and YbBi2ClO4 were investigated using a combination of…
The interplay between competing degrees of freedom can stabilize non-trivial magnetic states in correlated electron materials. Frustration-induced strong quantum fluctuations can evade long-range magnetic ordering leading to exotic quantum…
The structural and magnetic properties of the two-dimensional spin-$1/2$ depleted-kagome compound Cu$_7$(TeO$_3$)$_2$(SO$_4$)$_2$(OH)$_6$ are investigated using x-ray diffraction, magnetization, heat capacity, and $^1$H Nuclear Magnetic…
We study the magnetic properties of CaFeTi$_2$O$_6$ (CFTO) by high-field magnetization and specific heat measurements. While the magnetic susceptibility data yield a vanishingly small Curie-Weiss temperature, the magnetic moments are not…
Quantum fluctuations endow spin systems with surprisingly enriched magnetic phase diagrams. In frustrated magnets, strong quantum fluctuations boosted by either geometrical incompatibility or competitive exchange interactions stabilize…
Triangular Heisenberg antiferromagnets are prototypes of geometric frustration, even if for nearest-neighbor interactions quantum fluctuations are not usually strong enough to destroy magnetic ordering: stronger frustration is required to…