Squeezing and entanglement of a two-mode field in a four-level tripod atomic system

► The squeezing and entanglement of two squeezed fields preserve after their propagation through the four-level tripod-scheme atoms. ► The propagation at the same group velocity under EIT is convenient to quantifying the entanglement of two fields. ► The dephasing rates will degrade the entanglement and squeezing.