Physics – Condensed Matter – Strongly Correlated Electrons
Scientific paper
2004-01-29
Journal of Physics: Condensed Matter, Volume 16, Number 15, 21 April 2004, p. 2681-2687
Physics
Condensed Matter
Strongly Correlated Electrons
8 pages, 4 figures
Scientific paper
10.1088/0953-8984/16/15/019
We use a variational mean-field like approach, the coupled cluster method (CCM) and exact diagonalization to investigate the ground-state order-disorder transition for the square lattice spin-half XXZ model with two different nearest-neighbor couplings $J$ and $J'$. Increasing $J' > J$ the model shows in the isotropic Heisenberg limit a second-order transition from semi-classical N\'eel order to a quantum paramagnetic phase with enhanced local dimer correlations on the $J'$ bonds at about $J'_{c} \sim 2.5 ... 3 J$. This transition is driven by the quantum competition between $J'$ and $J$. Increasing the anisotropy parameter $\Delta> 1$ we diminish the quantum fluctuations and thus the degree of competition. As a result the transition point $J'_{c}$ is shifted to larger values. We find indications for a linear increase of $J'_{c}$ with $\Delta $, i.e. the transition disappears in the Ising limit $\Delta \to \infty$.
Darradi Rachid
Krueger Sven E.
Richter Jadwiga
No associations
LandOfFree
Influence of Ising-anisotropy on the zero-temperature phase transition in the square lattice spin-1/2 J-J' model does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Influence of Ising-anisotropy on the zero-temperature phase transition in the square lattice spin-1/2 J-J' model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Influence of Ising-anisotropy on the zero-temperature phase transition in the square lattice spin-1/2 J-J' model will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-533242