128 citations · 793 across the 55 of their papers we have counts for
13 papers · 1 filter
Classical ground states of spin lattices
Heinz-Jürgen Schmidt, Johannes Richter
We present a generalization of the Luttinger-Tisza-Lyons-Kaplan (LTLK) theory of classical ground states of Bravais lattices with Heisenberg coupling to non-Bravais lattices. It co…
Accuracy of the typicality approach using Chebyshev polynomials
H. Schlüter, F. Gayk, H. -J. Schmidt +2
Trace estimators allow to approximate thermodynamic equilibrium observables with astonishing accuracy. A prominent representative is the finite-temperature Lanczos method (FTLM) wh…
Observation of phase synchronization and alignment during free induction decay of quantum spins with Heisenberg interactions
P. Vorndamme, H. -J. Schmidt, Chr. Schröder +1
Equilibration of observables in closed quantum systems that are described by a unitary time evolution is a meanwhile well-established phenomenon apart from a few equally well-estab…
Supersymmetric spin-phonon coupling prevents odd integer spins from quantum tunneling
K. Irländer, H. -J. Schmidt, J. Schnack
Quantum tunneling of the magnetization is a phenomenon that impedes the use of small anisotropic spin systems for storage purposes even at the lowest temperatures. Phonons, usually…
Theory of ground states for classical Heisenberg spin systems V
Heinz-Jürgen Schmidt, Wojciech Florek
We formulate part V of a rigorous theory of ground states for classical, finite, Heisenberg spin systems. After recapitulating the central results of the parts I - IV previously pu…
Interpolation between low and high temperatures of the specific heat for spin systems
Heinz-Jürgen Schmidt, Andreas Hauser, Andre Lohmann +1
The high temperature expansion (HTE) of the specific heat of a spin system fails at low temperatures, even if it is combined with a Padé approximation. On the other hand we often h…
Exact ground state of a frustrated integer-spin modified Shastry-Sutherland model
Johannes Richter, Heinz-Jürgen Schmidt
We consider a two-dimensional geometrically frustrated integer-spin Heisenberg system that admits an exact ground state. The system corresponds to a decorated square lattice with t…
Exact ground states for coupled spin trimers
Heinz-Jürgen Schmidt, Johannes Richter
We consider a class of geometrically frustrated Heisenberg spin systems which admit exact ground states. The systems consist of suitably coupled antiferromagnetic spin trimers with…
Optimized implementation of the Lanczos method for magnetic systems
J. Schnack, P. Hage, H. -J. Schmidt
Numerically exact investigations of interacting spin systems provide a major tool for an understanding of their magnetic properties. For medium size systems the approximate Lanczos…
Universal properties of highly frustrated quantum magnets in strong magnetic fields
Oleg Derzhko, Johannes Richter, Andreas Honecker +1
The purpose of the present paper is two-fold. On the one hand, we review some recent studies on the low-temperature strong-field thermodynamic properties of frustrated quantum spin…
Exact eigenstates of highly frustrated spin lattices probed in high fields
J. Schnack, H. -J. Schmidt, A. Honecker +2
Strongly frustrated antiferromagnets such as the magnetic molecule {Mo72Fe30}, the kagome, or the pyrochlore lattice exhibit a variety of fascinating properties like low-lying sing…
Linear independence of localized magnon states
Heinz-Jürgen Schmidt, Johannes Richter, Roderich Moessner
At the magnetic saturation field, certain frustrated lattices have a class of states known as "localized multi-magnon states" as exact ground states. The number of these states sca…
Exact eigenstates and macroscopic magnetization jumps in strongly frustrated spin lattices
J. Richter, J. Schulenburg, A. Honecker +2
For a class of frustrated spin lattices including e.g. the 1D sawtooth chain, the 2D kagomé and checkerboard, as well as the 3D pyrochlore lattices we construct exact product eigen…