Mott-Hubbard LiCuVO $_4$绝缘体中激子二重态的椭圆偏振光谱研究
Exciton doublet in the Mott-Hubbard LiCuVO$_4$ insulator identified by spectral ellipsometry
摘要：
用椭圆偏振光谱法研究了LiCuVO $_{4}$（一种由共边CuO $_4$链组成的化合物）在（7-300）K的光谱范围（0.75 - 6.5）eV内的介电函数。对于沿链的光子极化，数据显示了一个弱的，但很好地解决了双峰结构中心在2.15和2.95 eV，其光谱权重是强烈增强冷却后的磁有序温度附近。我们确定这些功能作为一个激子双峰的莫特-哈伯德间隙出现的结果，最近的和下一个最近的邻居网站上的电子之间的库仑相互作用沿链。我们的研究结果和方法可以用来解决的作用，长程库仑排斥与掺杂氧化铜链和平面的化合物。
英文摘要：
Spectroscopic ellipsometry was used to study the dielectric function of LiCuVO$_{4}$, a compound comprised of chains of edge-sharing CuO$_4$ plaquettes, in the spectral range (0.75 - 6.5) eV at temperatures (7-300) K. For photon polarization along the chains, the data reveal a weak but well-resolved two-peak structure centered at 2.15 and 2.95 eV whose spectral weight is strongly enhanced upon cooling near the magnetic ordering temperature. We identify these features as an exciton doublet in the Mott-Hubbard gap that emerges as a consequence of the Coulomb interaction between electrons on nearest and next-nearest neighbor sites along the chains. Our results and methodology can be used to address the role of the long-range Coulomb repulsion for compounds with doped copper-oxide chains and planes.
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。
