Magnon dispersion and thermodynamics in CsNiF{sub 3}
We present an accurate transfer matrix renormalization group calculation of the thermodynamics in a quantum spin-1 planar ferromagnetic chain. We also calculate the field dependence of the magnon gap and confirm the accuracy of the magnon dispersion derived earlier through a 1/n expansion. We are thus able to examine the validity of a number of previous calculations and further analyze a wide range of experiments on CsNiF{sub 3} concerning the magnon dispersion, magnetization, susceptibility, and specific heat. Although it is not possible to account for all data with a single set of parameters, the overall qualitative agreement is good and the remaining discrepancies may reflect a departure from ideal quasi-one-dimensional model behavior. Finally, we present some indirect evidence to the effect that the popular interpretation of the excess specific heat in terms of sine-Gordon solitons may not be appropriate.
- Sponsoring Organization:
- (US)
- OSTI ID:
- 40203470
- Journal Information:
- Physical Review B, Vol. 63, Issue 22; Other Information: DOI: 10.1103/PhysRevB.63.224406; Othernumber: PRBMDO000063000022224406000001; 044122PRB; PBD: 1 Jun 2001; ISSN 0163-1829
- Publisher:
- The American Physical Society
- Country of Publication:
- United States
- Language:
- English
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