Abstract:
We consider the thermodynamics of the model of equal spin–spin interactions. We obtain exact expressions for the correlation functions and heat capacity of finite clusters applicable in the entire range of temperature and external fields. We analyze the obtained thermodynamic characteristics depending on the interaction parameters, the external magnetic field, and the number of particles in the cluster. We find an anomalous behavior of the heat capacity and other thermodynamic quantities due to elementary spin gap excitations occurring in the spectrum. The absence of a long-range order in the system is ensured by the presence of topological excitations (solitons). We study the effect of an anisotropic interaction parameter on the soliton structure.
Citation:
A. A. Khamzin, R. R. Nigmatullin, “Thermodynamics of the model of equal spin–spin interactions”, TMF, 165:1 (2010), 160–176; Theoret. and Math. Phys., 165:1 (2010), 1371–1386
A. A. Khamzin, R. R. Nigmatullin, “The NMR line shape of a system of nuclear spins with equal spin–spin coupling constants”, Theoret. and Math. Phys., 167:1 (2011), 496–505
Khamzin A.A., Nigmatullin R.R., Alekhin A.P., Sitdikov A.S., Nikitin A.S., “The NMR line shape of magneto-active nanoclusters in moveable nano-containers with self-similar stochastic dynamics”, International Conference on Resonances in Condensed Matter: Altshuler100, Journal of Physics Conference Series, 324, 2011
Khamzin A.A., Sitdikov A.S., Nikitin A.S., “Dynamics of nuclear spins with equal constants of spin-spin interaction”, Bulletin of the Russian Academy of Sciences: Physics, 75:4 (2011), 574–579