Abstract
A quantum version of the Niemeijer–van Leeuwen real-space renormalization-group method is used to study the temperature dependence of the two- and four-spin correlations in the quantum XY model on the triangular lattice. The first-order cumulant expansion results suggest, similarly to other methods, a low-temperature phase of an essentially different kind from that predicted for the classical model. The possible explanation of the origin of the spurious 2D Heisenberg-like nontrivial fixed point in some renormalization-group calculations is also proposed.
- Received 30 January 1995
DOI:https://doi.org/10.1103/PhysRevB.52.4313
©1995 American Physical Society