Enhanced multi-mode squeezing via a balanced regime in dual-four-wave mixing

The generation of multi-mode squeezing using four-wave mixing process has attracted considerable attention, offering significant potential for advancements in quantum communication, quantum key distribution, and quantum-enhanced sensing. In this paper, we propose a balanced regime within the dual-four-wave mixing (DFWM) process to theoretically generate quantum-enhanced multi-mode squeezed light. By operating at a plane-balanced regime, the relative intensity squeezing noise factor of the multi-mode beams can be made to approach zero theoretically, thus achieving perfect multi-mode squeezed states. Moreover, the generated beams at the plane-balanced regime exhibit quantum-enhanced entanglement superior to that of conventional four-wave mixing processes, offering significant implications for quantum information processing. The DFWM process can also be extended to multi-spatial-mode squeezing with a spatial-balanced regime, where the attainable squeezing degree is enhanced by a factor of G^N, where N denotes mode numbers and G denotes the gain, facilitating simply experimental implementation within a single atomic system. The proposed method paves the way for practical applications in high-precision measurements, robust quantum communication networks, and advanced quantum information processing systems.