PT Symmetry via Electromagnetically Induced Transparency

TL;DR

This paper presents a novel scheme to realize PT symmetry in optical systems using electromagnetically induced transparency in cold atomic ensembles, enabling controllable complex potentials with a single atomic species.

Contribution

The proposed method simplifies PT-symmetric system realization by using only one atomic species and combines EIT, optical lattice, and gain mechanisms.

Findings

Achieves PT symmetry with controllable complex potentials.

Utilizes a single atomic species for easier implementation.

Demonstrates the feasibility of atomic coherence in PT-symmetric optics.

Abstract

We propose a scheme to realize parity-time (PT) symmetry via electromagnetically induced transparency (EIT). The system we consider is an ensemble of cold four-level atoms with an EIT core. We show that the cross-phase modulation contributed by an assisted field, the optical lattice potential provided by a far-detuned laser field, and the optical gain resulted from an incoherent pumping can be used to construct a PT-symmetric complex optical potential for probe field propagation in a controllable way. Comparing with previous study, the present scheme uses only a single atomic species and hence is easy for the physical realization of PT-symmetric Hamiltonian via atomic coherence.