WICK AND GOLDSTONE THEOREMS FOR GENERAL SPIN; ANTIFERROMAGNETIC SPIN WAVES II.
Abstract
The analogues of Wick's theorem and of Goldstone's theorem, proved in the preceding paper (AD-624 720) for spin 1/2, are generalized to arbitrary spin. The proof is based on the Schwinger coupled-boson representation of spin operators. Quantum corrections to the spin wave modes in antiferromagnets are again considered, and it is shown that these corrections can be expanded in powers of 1/2Sz, where z is the number of nearest neighbors. For large S the 1/S factor presumably provides convergence, as assumed by Oguchi, whereas for S = 1/2 the expansion parameter reduces to 1/z, as discussed in the preceding paper. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1966
- Accession Number
- AD0629141
Entities
People
- H. B. Callen
- Yung-li Wang
Organizations
- University of Pennsylvania