Faster Preparation of Multi-qubit Entanglement with Higher Success Rates

A noteworthy discovery in recent research is that the process of two-qubit quantum entanglement preparation can be significantly accelerated near the exceptional point (EP) or spectral coalescence of non-Hermitian systems, as compared to conventional Hermitian setups. Nevertheless, a significant obstacle for quantum EP-based devices is their limited success rate in generating highly entangled states, stemming from an inherent trade-off relation between entanglement degree and success rate in all lossy EP systems. Our study demonstrates that this limitation can be effectively overcome by harnessing a truly parity-time (PT)-symmetric system, which possesses balanced gain and loss, thereby enabling maximal entanglement with rapid speed, high success rates, and greater resilience to non-resonant errors. We believe this approach can efficiently prepare multi-qubit entanglement and use not only bipartite but also tripartite entanglement as examples to illustrate, even when the precise gain-loss balance is not strictly maintained. Our analytical findings are in excellent agreement with numerical simulations, confirming the potential of PT-devices as a powerful tool for creating and engineering diverse quantum resources for applications in quantum information technology.