16 citations · 16 across the 1 of their papers we have counts for
6 papers
Ground-state phase diagram of the spin-1/2 square-lattice J1-J2 model with plaquette structure
O. Götze, S. E. Krüger, F. Fleck +2
Using the coupled cluster method for high orders of approximation and Lanczos exact diagonalization we study the ground-state phase diagram of a quantum spin-1/2 J1-J2 model on the…
Influence of quantum fluctuations on zero-temperature phase transitions between collinear and noncollinear states in frustrated spin systems
Sven E. Krüger, Johannes Richter
We study a square-lattice spin-half Heisenberg model where frustration is introduced by competing nearest-neighbor bonds of different signs. We discuss the influence of quantum flu…
Coupled Cluster Treatment of the XY model
D. J. J. Farnell, S. E. Krueger, J. B. Parkinson
We study quantum spin systems in the 1D, 2D square and 3D cubic lattices with nearest-neighbour XY exchange. We use the coupled-cluster method (CCM) to calculate the ground-state e…
The spin 1/2 Heisenberg star with frustration II: The influence of the embedding medium
Johannes Richter, Andreas Voigt, Sven E. Krüger +1
We investigate the spin 1/2 Heisenberg star introduced in J. Richter and A. Voigt, J. Phys. A: Math. Gen. {\bf 27}, 1139 (1994). The model is defined by $H=J_1 \sum_{i=1}^{N}{{\bf…
Square-lattice Heisenberg antiferromagnet with two kinds of nearest-neighbor regular bonds
N. B. Ivanov, S. E. Krüger, J. Richter
We study the zero-temperature phase diagram of a square-lattice Heisenberg antiferromagnet with two types of regularly distributed nearest-neighbor exchange constants, $J_1…
Integrable models of interacting quantum spins with competing interactions
Johannes Richter, Sven E. Krüger, Andreas Voigt +1
We present a class of exactly solvable quantum spin models which consist of two Heisenberg-subsystems coupled via a long-range Lieb-Mattis interaction. The total system is exactly…