It has been proposed that laser-induced relativistic plasma mirror can accelerate if the plasma has a properly tailored density profile. Such accelerating plasma mirrors can serve as analog black holes to investigate Hawking evaporation and the associated information loss paradox. Here we reexamine the underlying dynamics of mirror motion in a graded-density plasma to provide an explicit trajectory as a function of the plasma density and its gradient. Specifically, a decreasing plasma density profile (down-ramp) along the direction of laser propagation would in general accelerate the mirror. In particular, a constant-plus-exponential density profile would generate the Davies-Fulling trajectory with a well-defined analog Hawking temperature, which is sensitive to the plasma density gradient but not to the density itself. We show that without invoking nano-fabricated thin-films, a much lower density gas target at, for example, $\sim 1\times 10^{17}{\rm cm}^{-3}$, would be able to induce an analog Hawking temperature, $k_{_B}T_{_H}\sim 6.6 \times 10^{-2}{\rm eV}$, in the far-infrared region. We hope that this would help to better realize the experiment proposed by Chen and Mourou.

中文翻译：

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飞行等离子体反射镜穿过密度梯度目标的轨迹

已经提出，如果等离子体具有适当定制的密度分布，则激光诱导的相对论等离子体反射镜可以加速。这种加速等离子体镜可以作为模拟黑洞来研究霍金蒸发和相关的信息丢失悖论。在这里，我们重新研究了梯度密度等离子体中镜面运动的潜在动力学，以提供作为等离子体密度及其梯度函数的明确轨迹。具体而言，沿激光传播方向减小的等离子体密度分布（下降斜线）通常会加速反射镜。特别是，恒定加指数密度剖面将生成具有明确定义的模拟霍金温度的 Davies-Fulling 轨迹，该轨迹对等离子体密度梯度敏感，但对密度本身不敏感。我们表明，在不调用纳米制造薄膜的情况下，密度低得多的气体目标，例如，$\sim 1\times 10^{17}{\rm cm}^{-3}$，将能够在远红外区域诱导模拟霍金温度 $k_{_B}T_{_H}\sim 6.6 \times 10^{-2}{\rm eV}$。我们希望这将有助于更好地实现陈和穆柔提出的实验。