Quantum Entanglement in SU(3) Lattice Yang-Mills Theory at Zero and Finite Temperatures

We examine the entanglement properties of the Yang-Mills theory by calculating $\alpha$ entanglement entropy with $\alpha=2$ using a SU(3) quenched lattice gauge simulation both in the confinement and the deconfinement phases. In the confinement phase, the derivative of the $\alpha$ entropy with respect to the size $l$ of the subregion, whose entanglement properties are interested in, scales as $1/l^3$, and a clear discontinuity cannot be found within our statistical errors. The $\alpha$ entropy in the deconfinement phase saturates at large $l$. The saturation value is comparable with the thermal entropy of the pure Yang-Mills theory, indicating that the $\alpha$ entropy obeys the volume law at large $l$ in the deconfinement phase.