Deflection and manipulation of weak optical solitons by non-Hermitian electromagnetically induced gratings in Rydberg atoms

Based on a Rydberg-electromagnetically-induced-transparency (Rydberg-EIT) system, an electromagnetically induced grating (EIG) with parity-time (<inline-formula><tex-math id="M1">\begin{document}${\cal{PT}}$\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20220456_M1.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20220456_M1.png"/></alternatives></inline-formula>) symmetry is realized. The formation of solitons before the probe laser field reaching the EIG as well as its deflection when passing through the EIG are both investigated. It is found that due to the enhanced nonlinear optical effect of the Rydberg-EIT system, stable optical soliton can be formed with a very weak input light energy. In addition, it is found that by changing the gain/absorption coefficient of EIG, the period of EIG, and the nonlocality degree of optical Kerr nonlinear of the system, the deflection degree of the optical soliton can be effectively changed and manipulated. The research results of this work can provide a theoretical basis for the future applications of <inline-formula><tex-math id="M2">\begin{document}${\cal{PT}}$\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20220456_M2.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20220456_M2.png"/></alternatives></inline-formula>-symmetric EIG and may be useful in the fields of all-optical manipulation and optical information processing.