Theory of L-edge resonant inelastic x-ray scattering for magnetic excitations spectra in two-leg laddercuprate
Theory of L-edge resonant inelastic x-ray scattering for magnetic excitations spectra in two-leg laddercuprate
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两腿梯铜板磁激发谱的L边共振非弹性X射线散射理论
DOI：
10.1103/physrevb.85.224436
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发表时间：
2012
影响因子：
3.7
通讯作者：
Jun-ichi Igarashi
中科院分区：
文献类型：
--
作者：
Tatsuya Nagao;Jun-ichi Igarashi
研究了两臂自旋阶梯铜酸盐中自旋-液体基态铜边共振非弹性x射线散射(RIXS)的磁激发谱。应用作者发展的投影法，我们导出了磁性RIXS谱的公式，它们分别用变极化和保偏振通道中的单自旋和双自旋关联函数表示。单自旋关联函数包括单三重子激发和二三重子激发，它们分别通过选择梯级波矢量和0来提取。对SrCuO的应用表明，计算的RIXS谱很好地反映了两三重子连续谱的下界所显示的色散行为。一个例外是在零动量转移时没有强度，在实验中观察到了微弱但有限的强度。通过调整测量的几何构型，在RIXS实验中可以检测到围绕区域中心的一三子色散。在高能区观察到的弱强度可能归因于双自旋关联函数，这种关联函数在边缘RIXS谱上可以更清楚地检测到。
We study the magnetic excitation spectra of Cu-edge resonant inelastic x-ray scattering (RIXS) from the spin-liquid ground state in two-leg spin ladder cuprates. By applying the projection method developed by the present authors, we have derived the formulas of the magnetic RIXS spectra, which are expressed by one- and two-spin correlation functions in the polarization changing and preserving channels, respectively. The one-spin correlation function includes both one- and two-triplon excitations and they are picked up separately by choosing rung wave vectorsand 0, respectively. An application to SrCuOreveals that the calculated RIXS spectrum captures well the dispersive behavior shown by the lower boundary of two-triplon continuum. An exception is absence of the intensity at zero-momentum transfer where weak but finite intensity was observed in the experiment. By adjusting the geometrical configuration of the measurement, one-triplon dispersion around the zone center could be detectable in the RIXS experiment. The observed weak intensity in the higher-energy region might be attributed to the two-spin correlation function, which could be detected more clearly at the-edge RIXS spectra.