14 citations · 64 across the 9 of their papers we have counts for
9 papers
Quantum phase transition in the Plaquette lattice with anisotropic spin exchange
Andreas Voigt
I study the influence of anisotropic spin exchange on a quantum phase transition in the Plaquette lattice driven by the purely quantum effect of singlet formation. I study the infl…
Quantum disorder due to singlet formation: The Plaquette lattice
Andreas Voigt
I study the order/disorder transition due to singlet formation in a quantum spin system by means of exact diagonalization. The systems is build by spin 1/2 on a two-dimensional squ…
The quantum Heisenberg antiferromagnet on the Sierpinski Gasket: An exact diagonalization study
Andreas Voigt, Johannes Richter, Piotr Tomczak
We present an exact diagonalization study of the quantum Heisenberg antiferromagnet on the fractal Sierpinski gasket for spin quantum numbers s=1/2,s=1 and s=3/2. Since the fractal…
Marshall-Peierls sign rule in frustrated Heisenberg chains
Andreas Voigt, Johannes Richter
We consider the frustrated antiferromagnetic s=1 Heisenberg quantum spin chain with regard to the Marshall-Peierls sign rule (MPSR). By using exact diagonalization data we investig…
Magnetic model for Ba_2Cu_3O_4Cl_2
J. Richter, A. Voigt, J. Schulenburg +2
Ba_2Cu_3O_4Cl_2 consists of two types of copper atoms, Cu(A) and Cu(B). We study the corresponding Heisenberg model with three antiferromagnetic couplings, J_AA, J_BB and J_AB. We…
Marshall-Peierls sign rule for excited states of the frustrated J1-J2 Heisenberg antiferromagnet
A. Voigt, J. Richter, N. B. Ivanov
We present analytical and numerical calculations for some exited states of the frustrated J1-J2 spin-1/2 Heisenberg model for linear chains and square lattices. We consider the low…