A Three-Parameter Gram-Charlier Gaussian Representation of the Spectral Function of Spin Correlations
Abstract
A possible three-parameter Gram-Charlier form of the Gaussian diffusivity representation of the magnetic spin spectral function is evaluated for a restricted XY Heisenberg model, a linear chain of S = 1/2 spins with only transverse exchange at elevated temperature. A brief analytical background is presented for the method of wave-vector-dependent frequency moments, which are used to determine the approximate spectral function. The three-parameter form of the spectral function is compared with a previous corresponding two-parameter form and with an exact solution available for the restricted XY model. It is concluded that the postulated three-parameter Gram-Charlier Gaussian diffusivity, utilizing the additional information in the sixth frequency moment, offers a definite improvement in the representation of spin spectral functions and correlations.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1973
- Accession Number
- AD0775689
Entities
People
- Frederick A. Malinoski
Organizations
- Frankford Arsenal