Opening of the Haldane gap in anisotropic two- and four-leg spin ladders

Journal Article · Wed Dec 01 04:00:00 EST 1999 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PhysRevB.60.15230· OSTI ID:20217948

Kim, Eugene H ^[1]; Solyom, J ^[2]

---

1. Department of Physics, University of California, Santa Barbara, California 93106-9530 (United States)
2. Research Institute for Solid State Physics, P.O. Box 49, H-1525 Budapest, (Hungary)

We study the opening of the Haldane gap in two-leg and four-leg anisotropic spin ladders using bosonization and renormalization group methods, and we determine the phase diagram as a function of the interchain coupling and relative anisotropy J{sup z}/J{sup xy}. It is found that the opening of the Haldane gap is qualitatively different for the two cases considered. For the two-leg ladder the Haldane gap opens for arbitrarily small interchain coupling, independent of J{sup z}/J{sup xy}, and the Haldane phase exists in a large region of parameter space. For the four-leg ladder the opening of the Haldane gap is strongly dependent on both the interchain coupling as well as J{sup z}/J{sup xy}, and the Haldane phase exists only in a narrow region about the isotropic antiferromagnet. (c) 1999 The American Physical Society.

• OSTI ID: 20217948
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 22 Vol. 60; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANISOTROPY
ANTIFERROMAGNETISM
ENERGY GAP
HAMILTONIANS
RENORMALIZATION
SPIN
THEORETICAL DATA