We consider two Unruh-DeWitt detectors interacting with a massless, minimally coupled scalar field in a \((1+1)\) dimensional Reissner-Nordström black hole spacetime. In particular, one of the detectors, corresponding to Alice, is moving along an outgoing null trajectory. While the other detector carried by Bob is static. With this set-up, we investigate the entangling condition and the measure of the entanglement, concurrence, in the nonextremal and extremal scenarios. Our observations suggest, as expected, a qualitative similarity in characteristics of the entanglement between these two scenarios. However, we find quantitative differences between the nonextremal and extremal concurrences for a broad range of black hole charges. With moderately large detector transition energy, the extremal background always accounts for the larger entanglement than the nonextremal one. In contrast, with low detector transition energy, entanglement on the nonextremal background can be greater. Therefore, by adjusting the detector transition energy, one can perceive optimum entanglement from either the extremal or the nonextremal background.

我们考虑两个 Unruh-DeWitt 探测器与 \((1+1)\) 维 Reissner-Nordström 黑洞时空中的无质量、最小耦合标量场相互作用。特别是，对应于爱丽丝的探测器之一正在沿着传出零轨迹移动。而鲍勃携带的另一个探测器是静态的。通过这种设置，我们研究了非极值和极值场景中的纠缠条件以及纠缠、并发的度量。正如预期的那样，我们的观察结果表明，这两种情况之间的纠缠特征具有质的相似性。然而，我们发现大范围的黑洞电荷的非极值和极值并发之间存在数量差异。在探测器跃迁能量适中的情况下，极值背景总是比非极值背景产生更大的纠缠。相反，当探测器跃迁能量较低时，非极值背景上的纠缠可能会更大。因此，通过调整探测器跃迁能量，人们可以从极值或非极值背景感知最佳纠缠。