Auto-correlation Functions and Quantum Fluctuations of the Transverse Ising Chain by the Quantum Transfer Matrix Method
arXiv:1009.0066
Abstract
The Quantum Transfer Matrix method based on the Suzuki-Trotter formulation is extended to dynamical problems. The auto-correlation functions of the Transverse Ising chain are derived by this method. It is shown that the Trotter-directional correlation function is interpreted as a Matsubara's temperature Green function and that the auto-correlation function is given by analytic continuation of the Green function. We propose the Trotter-directional correlation function is a new measure of the quantum fluctuation and show how it works well as a demonstration.
18 pages, 9 figures