AI 中文总结
研究三方量子拉比模型中的静态纠缠结构与绝热贝尔态制备，通过分析能谱和纠缠变化，识别本征分支，给出解析标准，用三态有效模型解释现象，并通过有限时间线性斜坡确定高保真度所需参数，揭示了耦合对纠缠及制备的作用。
AI 中文摘要
三方量子拉比模型通过集体自旋 - 振子相互作用将两个量子比特与一个玻色子模式耦合，为研究两量子比特纠缠提供了简单设置。在零失谐极限下，能谱的三重态部分分裂为具有零和最大纠缠的分支，而反对称单重态阶梯保持完全解耦。在三重态扇区内，有限失谐将这些分支之间的交叉变为避免交叉并重新分配纠缠。我们识别出一个本征分支，其纠缠通过这种避免交叉混合从近零增长到近最大值。弱耦合能级排序给出了该本征分支是否具有可分弱耦合端点的简单解析标准。一个三态有效模型解释了随着耦合增加贝尔态分量如何占主导。我们还使用集体耦合的有限时间线性斜坡来确定高贝尔态保真度所需的最终耦合和斜坡时间。这些结果展示了集体自旋 - 振子耦合如何重组谱纠缠并将静态分支结构与有限时间贝尔态制备联系起来。
英文摘要
The tripartite quantum Rabi model couples two qubits to a bosonic mode through a collective spin-oscillator interaction, providing a simple setting for studying two-qubit entanglement. In the zero-detuning limit, the triplet part of the spectrum splits into branches with zero and maximal entanglement, while the antisymmetric singlet ladder remains exactly decoupled. Within the triplet sector, finite detuning turns the crossings between these branches into avoided crossings and redistributes this entanglement. We identify an eigenbranch whose entanglement grows from nearly zero to a nearly maximal value through such avoided-crossing mixing. The weak-coupling level ordering yields a simple analytic criterion for whether this eigenbranch has a separable weak-coupling endpoint. A three-state effective model explains how the Bell-state component becomes dominant as the coupling increases. We further use a finite-time linear ramp of the collective coupling to benchmark the final coupling and ramp time required for high Bell-state fidelity. These results show how collective spin-oscillator coupling reorganizes spectral entanglement and connects static branch structure to finite-time Bell-state preparation.
Comments15 pages, 9 figures
