Efficient and controlled symmetric and asymmetric Bell-state transfers in a dissipative Jaynes–Cummings model

Realizing efficient and controlled state transfers is necessary for implementing a wide range of classical and quantum information protocols. Recent studies have demonstrated that both asymmetric and symmetric state transfers can be achieved by encircling an exceptional point (EP) in non-Hermitian (NH) systems. However, the application of this phenomenon has been restricted to scenarios where an EP exists in single-qubit systems and is associated with a specific type of dissipation. In this work, we demonstrate efficient and controlled symmetric and asymmetric Bell-state transfers by modulating system parameters within a Jaynes–Cummings model while accounting for atomic spontaneous emission and cavity decay. The effective suppression of nonadiabatic transitions enables a symmetric exchange of Bell states irrespective of the encircling direction. Furthermore, we report a counterintuitive finding: the presence of an EP is not indispensable for implementing asymmetric state transfers in NH systems. We achieve perfect asymmetric Bell-state transfers even in the absence of an EP by dynamically orbiting around an approximate EP. Our work presents an approach to effectively and reliably manipulate entangled states with both symmetric and asymmetric characteristics, through dissipation engineering in NH systems.