Abstract
Influence of PT symmetry on the Goos-Hänchen (GH) shift in the reflected light is presented for an ensemble of atomic medium in a cavity, in the configuration of four-level N-type (Rb87 atoms) systems driving by two copropagating strong laser fields and a weak probe field. The atom-field interaction follows the realization of PT symmetry by adjusting the coupling field detunings [J. Sheng, Phys. Rev. A 88, 041803(R) (2013)PLRAAN1050-294710.1103/PhysRevA.88.041803]. A giant enhancement for the GH shift in the reflected light is revealed when the PT-symmetry condition is satisfied. © 2015 American Physical Society.