Abstract
The Master equation of the kinetic Ising model with spin-flip and spin-exchange dynamics is written in a second quantized in terms of Pauli operators. The introduction of weighted transition rates allows a general formulation in accordance with the principle of detailed balance. Static and dynamic correlation functions are calculated. The structure factor reveals three different relaxation times already in an extended mean-field approximation. Additionally, we derive a nonlinear evolution equation for the magnetization under the influence of nonthermal external noise. Already in lowest order, the correlation function offers a stretched-exponential behavior with a universal exponent \ensuremath{\sigma}=4(d+2) below the critical dimensionality ${\mathit{d}}_{\mathit{c}}$=2. A one-loop renormalization group approach is used to calculate the critical exponents for the growth of the magnetization. The value of the growth exponent \ensuremath{\beta}=2(2-d)(8+d) is supported by simulations in one dimension. \textcopyright{} 1996 The American Physical Society.
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