MAGNETIC EXCITATIONS AND DOUBLE GAP IN THE S=1/2 LINEAR CHAIN QUANTUM ANTIFERROMAGNET BaCu{sub 2}Si{sub 2}O{sub 7}
The magnetic excitation spectrum of the ideal S=1/2 1-dimensional quantum antiferromagnet (AF), contains no single-mode contributions, and, in fact, can be described as a 2-particle continuum of spinons. Chain-MF theory predicts that a weakly coupled chains system becomes ordered at low temperatures. In the ordered state a sharp magnon excitation is present. The continuum persists, but is separated from the magnon branch by an appreciable energy gap. On the other hand, if weakly coupled chains are described through the 1/S expansion of the conventional Holstein-Primakov spin wave theory, one finds a longitudinal 2-magnon continuum and a transverse 3-magnon continuum that start immediately above the spin wave energy.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research (ER) (US)
- DOE Contract Number:
- AC02-98CH10886
- OSTI ID:
- 759036
- Report Number(s):
- BNL-67296; KC020201; R&D Project: PO10; KC020201; TRN: AH200035%%28
- Resource Relation:
- Other Information: The dates of this experiment were 11/10/1999--11/17/1999; PBD: 16 Mar 2000
- Country of Publication:
- United States
- Language:
- English
Similar Records
Extended Scattering Continua Characteristic of Spin Fractionalization in the Two-dimensional Frustrated Quantum Magnet Cs2CuCl4Observed by Neutron Scattering
Self-consistent mean-field theory of a spin-1 antiferromagnetic chain