title: Tunable nonlinear parity-time-symmetric defect modes with an atomic cell.
abstract: We propose a scheme of creating a tunable highly nonlinear defect in a one-dimensional photonic crystal. The defect consists of an atomic cell filled in with two isotopes of three-level atoms. The probe-field refractive index of the defect can be made parity-time (PT) symmetric, which is achieved by proper combination of a control field and of Stark shifts induced by a far-off-resonance field. In the PT-symmetric system, families of stable nonlinear defect modes can be formed by the probe field.
authors: Chao
authors: C
authors: Hang
authors: Dmitry A
authors: DA
authors: Zezyulin
authors: Vladimir V
authors: VV
authors: Konotop
authors: Guoxiang
authors: G
authors: Huang