Three‐Mode Squeezing of Simultaneous and Ordinal Cascaded Four‐Wave Mixing Processes in Rubidium Vapor

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Multipartite quantum entanglement plays a vital role in both fundamental science and quantum applications. The cascaded four‐wave mixing (FWM) process is an effective method to prepare multipartite entanglement, however, the physical nature of entanglement based on different cascading paths, i.e., simultaneous cascaded FWM (SC‐FWM) and ordinal cascaded FWM (OC‐FWM), has not yet been conclusively determined. In this article, tunable continuous‐variable (CV) triple‐mode entanglement is proposed to be generated by using both the SC‐FWM and OC‐FWM schemes. The simulation results reveal that the absorption/dispersion properties of the two nonlinear processes can be efficiently tuned by varying the optical parameters (i.e., the photon detuning and the nonlinear susceptibility), resulting in triple‐mode CV entanglement with tunable properties. Compared with the OC‐FWM scheme, the SC‐FWM scheme has a broader entanglement bandwidth and a higher degree of entanglement, where the tripartite entanglement region is 4.38% larger than that of the OC‐FWM scheme. Furthermore, these results indicate that the SC‐FWM scheme has a more compact and stable mode structure with better entanglement performance. Such tunable optical triple‐mode entanglement may find applications in specific quantum communication protocols and pave the way for implementing and manipulating multichannel quantum networks.

Section: Introductionmentioning

confidence: 99%

Tunable Continuous‐Variable Tripartite Entanglement via Simultaneous and Ordinal Cascaded Nonlinear Processes

Zhai,

Wen,

Zhang

et al. 2024

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“…Additionally, the three modes with dressing-energy-level-cascaded FWM process has also been implemented. [43,44] Two different frequency pump beams allow for the generation of entangled modes with rich frequencies. Meanwhile, the internal dressing field can be used to modulate atomic coherence and construct multiple quantum coherent channels, resulting in a significant extension of entanglement mode number and quantum information capacity.…”

Section: Introductionmentioning

confidence: 99%

Reconfigurable Hexapartite Cluster States by Four‐Wave Mixing Processes with a Spatially Structured Pump

Zhang,

Guo,

Jing

2023

The universal quantum computation provides a new paradigm for information processing. One feasible approach is measurement‐based one‐way quantum computation utilizing cluster states. Generally, the generation of cluster states with different structures for implementing on‐demand quantum computation needs different experimental setup, which limits its scalability. Here, the reconfigurable hexapartite cluster states created by postprocessing the quadrature information of hexapartite entangled state are demonstrated. Without altering the experimental layout, nine quantum correlated states with different structures, especially three cluster states, are implemented. In particular, such method can effectively reduce the excess noise introduced by creating cluster states under limited squeezing resources. This approach provides an avenue for realizing large‐scale reconfigurable cluster states without changing the experimental architecture.

Non‐Hermitian Control of Multimode Duan‐PPT Criteria and Steering in Energy‐Level Cascaded Four‐Wave Mixing Processes

Wei,

Huang,

et al. 2024

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The non‐Hermitian singularity control of multimode entanglement in the energy‐level cascaded four‐wave mixing system within a single atomic vapor is of great significance and importance. In this study, a non‐Hermiticity system by means of quasi‐quantization of energy‐band based on non‐Hermiticity systems is constructed. By employing atomic coherence in the non‐Hermiticity system, high‐dimensional quantized photon correlations underdressed field‐induced parity‐time (PT) symmetry and symmetry breaking through the quantization of energy levels are studied. Such a phenomenon happens at microscopic (nanoscale) when the eigenvalues of dressed energy‐level and multimode entanglement are considered for both real and imaginary parts symmetry breaking. Double dressing effect is observed with more coherent channels and larger information capacity than single dressing in the energy‐level cascaded four‐wave mixing system. The study found that the splitting of the real part is larger than an imaginary part in a second‐order system, and the imaginary part splitting is also greater than the real part splitting in a third‐order system. The real part (in phase) is constructive dressing quantization, and the imaginary (out of phase) is destructive dressing quantization. Exceptional points (EP points) can be used to enhance sensitivity detection of entanglement quantum state.