Enhanced asymmetric entanglement dynamics at higher-order exceptional points via optomechanical induced squeezing

The exotic entanglement dynamics associated with exceptional points (EP) have been explored in a ring mechanical system, which consists of a phase-dependent phonon-hopping interaction and two phonon-squeezing interactions. By modulating the gauge-invariant phase of the system, the spontaneous $\mathcal{PT}$-symmetry breaking can be generated, enabling the realization of higher-order EPs, such as second- and third-order EPs. The entanglement dynamics are strongly dependent on the orders of the EP. Specifically, both bipartite and tripartite entanglements emerge near the second-order EP, while the third-order EP leads to optimal bipartite entanglement with vanishing tripartite entanglement. Moreover, the asymmetric feature of the bipartite entanglement can be controlled by tuning the parity of the third-order EP through modulation of the system's gauge-invariant phase. The work indicates that the entanglement dynamics associated with EPs may provide a useful platform for realizing non-Hermiticity-enhanced quantum information processing.