2000/04/07 by A. Oosawa, Oosawa, A., T. Kato +13
Physics and Astronomy · #Condensed Matter (cond-mat) #FOS: Physical sciences #cond-mat
paper · pdf · doi:10.48550/arxiv.cond-mat/0004108
8 pages, revtex, 10 eps figures
arxiv created 2000/04/07 · arxiv updated 2009/11/30
Single-crystal neutron inelastic scattering was performed in order to investigate the magnetic excitations in the spin gap system TlCuCl3. The constant-\bf Q energy scan profiles were collected in the a^*-c^* plane. Three excitations are observed for E≤15 meV. One of the excitations is identified to be magnetic excitation. The lowest magnetic excitation with E∼ 0.5 meV occurs at \bf Q=(1, 0, 1), as observed in KCuCl3. The dispersion relation of the magnetic excitation can be fitted to the dispersion formula derived from the weakly coupled dimer model. The intradimer interaction is evaluated as J=5.23 meV, which coincides with the value estimated from the susceptibility data. However, one of the interdimer interactions obtained is so large that the weakly coupled dimer model is broken down.