Dynamical correlation functions of the transverse spin and energy density for the one-dimensional spin-½ Ising model with a transverse field
T. N. Tommet, David L. Huber
Dynamical correlation functions for the transverse (along the direction of the field) spin and energy densities are calculated for the one-dimensional spin-\textonehalf{} Ising model with a transverse field $H=\ensuremath{-}\ensuremath{\Gamma}{\ensuremath{\Sigma}}_{i}{S}_{i}^{x}\ensuremath{-}J{\ensuremath{\Sigma}}_{i}{S}_{i}^{z}{S}_{i+1}^{z}$. Explicit results are obtained for $〈{{S}^{x}(q, \ensuremath{\omega}){S}^{x}(\ensuremath{-}q)}〉$, $〈{E(q, \ensuremath{\omega}), E(\ensuremath{-}q)}〉$, and their Fourier transforms in the limits $T=\ensuremath{\infty}$ and $T=0$ and for the autocorrelation functions $〈{{S}_{i}^{x}, {S}_{i}^{x}(t)}〉$ and $〈{{E}_{i}, {E}_{i}(t)}〉$ in the same limits. The results are discussed with special attention given to the coupling of the transverse spin component and energy densities.
Physical review. B, Solid state•Jan 1, 1975•28 citations