The decoherence effect of qubit in 1D transverse Ising model

With the development of lab technology, low-order correlation function can no longer describe main effect decoherence in quantum many-body system, so it is imperative to study higher-order system. In this paper, discussed analytically 1D transverse Ising model, and searched when third-order or higher functions play a key role effect. Under cases strong coupling long coherence time, indicated that high-order cannot be ignored, approximation classical Markov process limited. But well case weak short time.