论文标题
关于检测真空双折射的海森堡极限
On the Heisenberg limit for detecting vacuum birefringence
论文作者
论文摘要
量子电动力学预测真空作用为非线性培养基，包括诸如双折射之类的效果。但是，对于实验可用的场强度，这种真空极化性极小，因此很难测量。与量子计量学的海森堡限制相比，我们研究了给定的强场（泵场）中这种检测的最低要求。使用激光脉冲作为探针场，我们发现其能量必须超过一定阈值，具体取决于相互作用时间。但是，在该阈值（即海森伯格极限）上检测需要高度非线性的测量方案 - 而对于普通的线性启发方案，所需的能量（Poisson或Shot噪声限制）较大。最后，我们从这个角度讨论了一些当前考虑的实验场景。
Quantum electrodynamics predicts the vacuum to behave as a non-linear medium, including effects such as birefringence. However, for experimentally available field strengths, this vacuum polarizability is extremely small and thus very hard to measure. In analogy to the Heisenberg limit in quantum metrology, we study the minimum requirements for such a detection in a given strong field (the pump field). Using a laser pulse as the probe field, we find that its energy must exceed a certain threshold depending on the interaction time. However, a detection at that threshold, i.e., the Heisenberg limit, requires highly non-linear measurement schemes - while for ordinary linear-optics schemes, the required energy (Poisson or shot noise limit) is much larger. Finally, we discuss several currently considered experimental scenarios from this point of view.
