Nonreciprocal slow or fast light in anti-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi mathvariant="script">PT</mml:mi></mml:math>-symmetric optomechanics
Meiyu Peng, Hui-Lai Zhang, Qian Zhang, Tian-Xiang Lu, Imran M. Mirza, Hui Jing
Abstract
Non-Hermitian systems with anti-parity-time $(\mathrm{a}\mathcal{PT})$ symmetry have revealed rich physics beyond conventional systems. Here, we study optomechanics in an $\mathrm{a}\mathcal{PT}$-symmetric spinning resonator and show that, by tuning the rotating speed to approach the exceptional point (EP) or the non-Hermitian spectral degeneracy, nonreciprocal light transmission with a high isolation ratio can be realized. Accompanying this process, nonreciprocal group delay or advance is also identified in the vicinity of EP. Our work sheds light on manipulating laser propagation with optomechanical EP devices and, in a broader view, can be extended to explore a wide range of $\mathrm{a}\mathcal{PT}$-symmetric effects, such as $\mathrm{a}\mathcal{PT}$-symmetric phonon lasers, $\mathrm{a}\mathcal{PT}$-symmetric topological effects, and $\mathrm{a}\mathcal{PT}$-symmetric force sensing or accelerator.