Dynamics of the Bloch vector in the thermal Jaynes-Cummings model

摘要: In this paper, we investigate the dynamics of Bloch vector a single two-level atom which interacts with quantized electromagnetic field mode according to Jaynes-Cummings model, where is initially prepared in thermal state. The time evolution $\mathbit{S}(t)$ seems be complete disorder because distribution initial state field. Both norm and direction oscillate hard their periods seem infinite. We observe that trajectory two- or three-dimensional space does not form closed path. To remove fast frequency oscillation from trajectory, take average $\mathbit{S}(t)$. examine histogram ${\phantom{|}{S}_{z}(n\ensuremath{\Delta}t)|n=0,1,\dots{},N}$ for small $\ensuremath{\Delta}t$ large $N$. It represents an absolute value derivative inverse function ${S}_{z}(t)$. [When $y={S}_{z}(t)$ multivalued function, summation values its derivatives at points whose real parts are equal $y$ on Riemann surface.] dependence variance temperature estimate lower bound entanglement between