论文标题
通过高纯度偏振法解散X射线二分法和双折射
Disentangling X-ray dichroism and birefringence via high-purity polarimetry
论文作者
论文摘要
高刷子同步辐射源为X射线极化分析开辟了新的途径，远远超出了光学结构域中的常规极化法。通过线性X射线极化器以交叉设置的极化灭绝比下降至10 $^{ - 10} $。这使该方法对探测最微小的光学各向异性敏感，例如，由于真空双发性双重性和二分性能而在强场上发生。在这里，我们表明可以使用高纯度极化法以最大的灵敏度和光谱分辨率揭示凝结物质系统中的电子各向异性。以Cuo和La $ _2 $ CUO $ _4 $为基准系统，我们对Cu k-a-Ab-Ab-Ab-Ab-Ab-Ab-Ab-Ab-Ab-Ab-a-Ab-Ab-Ab-Ab-Ab-Ab-Ab-apsoraging Edge进行了全面表征，它们将其分为二分性和双重贡献。在衍射限制的同步子辐射源和X射线激光器下，可以实现极化的灭绝比为10 $^{ - 12} $，我们的方法具有评估极端电磁场中量子真空的双重折射和二分法的潜力。
High-brilliance synchrotron radiation sources have opened new avenues for X-ray polarization analysis that go far beyond conventional polarimetry in the optical domain. With linear X-ray polarizers in a crossed setting polarization extinction ratios down to 10$^{-10}$ can be achieved. This renders the method sensitive to probe tiniest optical anisotropies that would occur, for example, in strong-field QED due to vacuum birefringence and dichroism. Here we show that high-purity polarimetry can be employed to reveal electronic anisotropies in condensed matter systems with utmost sensitivity and spectral resolution. Taking CuO and La$_2$CuO$_4$ as benchmark systems, we present a full characterization of the polarization changes across the Cu K-absorption edge and their separation into dichroic and birefringent contributions. At diffraction-limited synchrotron radiation sources and X-ray lasers, where polarization extinction ratios of 10$^{-12}$ can be achieved, our method has the potential to assess birefringence and dichroism of the quantum vacuum in extreme electromagnetic fields.
