Abstract
In this work, we show that the quantum compass model on a square lattice can be mapped to a fermionic model with local-density interaction. We introduce a mean-field approximation where the most important fluctuations, those perpendicular to the ordering direction, are taken into account exactly. It is found that the quantum phase transition point at J(x)=J(z) marks a first-order phase transition. We also show that the mean-field result is robust against the remaining fluctuation corrections up to the second order.
Published in:
Physical Review B 75,14 (2007) 144401;
Link to original published article:
http://dx.doi.org/10.1103/PhysRevB.75.144401
Keywords
Physics, Condensed Matter
Date of Version
January 2007
Recommended Citation
Chen, H. D.; Fang, C.; Hu, J. P.; and Yao, H., "Quantum phase transition in the quantum compass model" (2007). Department of Physics and Astronomy Faculty Publications. Paper 739.
https://docs.lib.purdue.edu/physics_articles/739