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WANG, HT; SHEN, JL; LI, KR; SU, ZB; WANG, HT , CHINESE CTR ADV SCI & TECHNOL,WORLD LAB,POB 8730,BEIJING 100080,PEOPLES R CHINA. | |
SELF-CONSISTENT MEAN-FIELD THEORY OF A SPIN-1 ANTIFERROMAGNETIC CHAIN | |
Source Publication | PHYSICAL REVIEW B |
Keyword | One-dimensional Antiferromagnets Ground-state Properties Monte-carlo Calculation Quantum Energy-gap Haldane-gap Heisenberg Chain Wave Theory Dynamical Properties Uniaxial Anisotropy Neutron-scattering |
Abstract | We develop an extended self-consistent mean-field approach to study a spin-1 antiferromagnetic (AF) chain with the Hamiltonian H=SIGMA(i) [S(i)(x)S(i+1)x + S(i)(y)S(i+1)y + lambdaS(i)(z)S(i+1)z + D(S(i)z)2] based on Anderson's spin-wave theory. The ground-state energy changes little compared with the traditional spin-wave theory and the excitation spectrum shows a gap which lends support to Haldane's conjecture. At the Heisenberg point (lambda = 1,D = 0), the ground-state energy and the gap are - 1. 3505 and 0.3914, respectively. In the Heisenberg-Ising case lambda > 0, D = 0), the gap decreases when lambda goes down from 1 and at a critical lambda(c) > 0 the pp goes to 0, while for the single-ion anisotropy (lambda = 1, D > 0) the gap decreases with the increasing of D and at a critical value D(c) the gap goes to 0. These results agree well with those of other theoretical methods and experiments. We study the one-magnon excitation spectrum carefully and suggest an explanation for its crossing with the two-magnon excitation spectrum at low momentum. We estimate the crossing occurring at k congruent-to 0.3pi. The results agree well with the very recent theoretical and experimental results. The picture of the Haldane gap is discussed from our extended self-consistent mean-field ground state and many interesting properties of the spin-1 AF chain are discussed. |
1994 | |
ISSN | 0163-1829 |
Volume | 49Issue:18Pages:12805-12812 |
Subject Area | Physics |
Indexed By | SCI |
Document Type | 期刊论文 |
Identifier | http://ir.itp.ac.cn/handle/311006/11913 |
Collection | SCI期刊论文 |
Corresponding Author | WANG, HT , CHINESE CTR ADV SCI & TECHNOL,WORLD LAB,POB 8730,BEIJING 100080,PEOPLES R CHINA. |
Recommended Citation GB/T 7714 | WANG, HT,SHEN, JL,LI, KR,et al. SELF-CONSISTENT MEAN-FIELD THEORY OF A SPIN-1 ANTIFERROMAGNETIC CHAIN[J]. PHYSICAL REVIEW B,1994,49(18):12805-12812. |
APA | WANG, HT,SHEN, JL,LI, KR,SU, ZB,&WANG, HT , CHINESE CTR ADV SCI & TECHNOL,WORLD LAB,POB 8730,BEIJING 100080,PEOPLES R CHINA..(1994).SELF-CONSISTENT MEAN-FIELD THEORY OF A SPIN-1 ANTIFERROMAGNETIC CHAIN.PHYSICAL REVIEW B,49(18),12805-12812. |
MLA | WANG, HT,et al."SELF-CONSISTENT MEAN-FIELD THEORY OF A SPIN-1 ANTIFERROMAGNETIC CHAIN".PHYSICAL REVIEW B 49.18(1994):12805-12812. |
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