
Department of Physics Papers
Document Type
Journal Article
Date of this Version
2-1-1990
Publication Source
Physical Review B
Volume
41
Issue
4
Start Page
2449
Last Page
2460
DOI
10.1103/PhysRevB.41.2449
Abstract
We calculate the ground-state energy of an isotropic quantum Heisenberg ferromagnet on an hexagonal lattice with ferromagnetic exchange interactions J1 and J’ between nearest neighbors in the same basal plane and adjacent basal planes and, respectively, competing interactions J2 and J3 between second- and third-nearest neighbors in the same basal plane, respectively. When the ground-state energy of a helical state with wave vector Q is expanded for small Q as EG(Q)=E0+E2Q2+E4Q4+...., then the coefficients E2 and E4 can be evaluated exactly at zero temperature, with the result that E2 is given by its classical (S→∞) value, whereas E4 has quantum corrections. At the ferromagnet-helix transition (at which E2=0) E4 is positive for S=∞ indicating that this transition is continuous, whereas as S−1 is nonzero, a region develops wherein the transition becomes discontinuous.
Recommended Citation
Rastelli, E., & Harris, A. (1990). First-Order Phase Transition Induced by Quantum Fluctuations in Heisenberg Helimagnets. Physical Review B, 41 (4), 2449-2460. http://dx.doi.org/10.1103/PhysRevB.41.2449
Date Posted: 12 August 2015
This document has been peer reviewed.
Comments
At the time of publication, author A. Brooks Harris was affiliated with Tel Aviv University. Currently, he is a faculty member in the Physics Department at the University of Pennsylvania.