arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 1507.02795cond-mat.str-el
收藏

基于详细电子能带结构的La $_2$ CuO $_4$中$L$边共振非弹性X射线散射的理论研究

Theoretical Study of $L$-edge Resonant Inelastic X-ray Scattering in La$_2$CuO$_4$ on the Basis of Detailed Electronic Band Structure

Takuji Nomura

摘要:

我们在详细的电子能带结构的基础上,理论上研究了高$T_c$铜氧化物超导体La $_2$ CuO $_4$的典型母体化合物中Cu $L_3$边的共振非弹性X射线散射(RIXS)。我们构建了一个现实的和精确的紧束缚模型,采用最大本地化的Wannier函数来自第一性原理电子结构计算,然后考虑到d电子之间的库仑排斥在每个Cu网站。在Hartree-Fock近似下描述反铁磁基态,并在随机相位近似(RPA)下考虑RIXS中间态的电子关联。计算的RIXS光谱符合实验观察到的功能,包括低能量磁振子激发,$d$ - $d$激发,和电荷转移激发,在很宽的激发能量范围。特别是,我们强调光子偏振依赖的重要性:磁振子激发的强度和$d$ - $d$激发的光谱结构不仅显著依赖于入射光子的偏振方向,而且还依赖于出射光子的偏振方向。结果表明,当入射光子和出射光子的偏振方向相互垂直时,单磁振子激发强度最大。

英文摘要:

We study theoretically resonant inelastic x-ray scattering (RIXS) at the Cu $L_3$-edge in a typical parent compound of high-$T_c$ cuprate superconductors La$_2$CuO$_4$ on the basis of a detailed electronic band structure. We construct a realistic and precise tight-binding model by employing the maximally-localized Wannier functions derived from a first-principles electronic structure calculation, and then take account of the Coulomb repulsion between d electrons at each Cu site. The antiferromagnetic ground state is described within the Hartree-Fock approximation, and take account of electron correlations in the intermediate states of RIXS within the random-phase approximation (RPA). Calculated RIXS spectra agree well with the experimentally observed features including low-energy magnon excitation, $d$-$d$ excitations, and charge-transfer excitations, over a wide excitation-energy range. In particular, we stress the importance of photon polarization dependence: the intensity of magnon excitation and the spectral structure of $d$-$d$ excitations depend significantly not only on the polarization direction of incident incoming photons but also that of outgoing photons. It is demonstrated that the single-magnon excitation intensity is maximized when the polarization directions of incoming and outgoing photons are perpendicular to each other.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑