论文标题
双重和不均匀媒体中的旋转噪声
Spin noise in birefringent and inhomogeneous media
论文作者
论文摘要
众所周知，培养基的线性双折射本质上阻碍了测量法拉第效应的效果。因此，光学各向异性材料从未被视为基于法拉第旋转的自旋噪声光谱（SNS）的对象。我们在理论上和实验上都表明，强烈的光学各向异性可能严重抑制了培养基的常规法拉第旋转，实际上不会影响空间不相关的自旋波动的测量。该结果的重要结果是，法拉第旋转噪声也应对空间不均匀的双折射不敏感，这使得SNS适用于广泛的光学各向异性和不均匀材料。我们还表明，双折射媒体提供了额外的机会来测量空间自旋相关性。在4 $ f $ -4 $ f $ nd $^{3+} $ ions cawo $ _4 $和liyf $ _4 $ Crystals中进行的4 $ f $ f $ nd $^{3+} $ ions的实验测量结果的结果非常同意该理论。
It is known that linear birefringence of the medium essentially hinders measuring the Faraday effect. For this reason, optically anisotropic materials have never been considered as objects of the Faraday-rotation-based spin noise spectroscopy (SNS). We show, both theoretically and experimentally, that strong optical anisotropy that may badly suppress the regular Faraday rotation of the medium, practically does not affect the measurement of the spatially uncorrelated spin fluctuations. An important consequence of this result is that the Faraday-rotation noise should be also insensitive to spatially nonuniform birefringence, which makes the SNS applicable to a wide class of optically anisotropic and inhomogeneous materials. We also show that the birefringent media provide additional opportunity to measure spatial spin correlations. Results of the experimental measurements of the spin-noise spectra performed on 4$f$--4$f$ transitions of Nd$^{3+}$ ions in the CaWO$_4$ and LiYF$_4$ crystals well agree with the theory.
