Journal of Physics C Solid State Physics
Temperature dependence of the transverse spin in the transverse Ising model
Lui Lam, Armin Bunde A
Abstract
Rigorous upper and lower bounds on the temperature dependence of the transverse spin in the transverse Ising model are calculated. The mean field approximation is shown to be identical to the lower bound in the limit of strong transverse field. Other approximate and sometimes conflicting calculations in the literature as well as experimental results are discussed and compared with the authors' exact bounds.