Schülzgen A, Kawabe Y, Hanamura E, Yamanaka A, Blanche P A, Lee J, Sato H, Naito M, Dan N T, Uchida S, Tanabe Y, Peyghambarian N
Phys Rev Lett. 2001 Apr 2;86(14):3164-7. doi: 10.1103/PhysRevLett.86.3164.
Combining linear absorption and nonlinear third harmonic generation (THG) experiments, we investigate details of the electronic structure of the highly correlated electronic system in La2CuO4. We demonstrate strong THG mainly due to the charge transfer excitation from O (2p(sigma)) to Cu (3d(x2-y2)). The THG spectrum shows pronounced features due to three-photon and two-photon resonance enhancement as well as quantum interference effects. We obtain excellent agreement with a THG spectrum calculated in terms of the excitonic cluster model and can identify both odd and even symmetry excitation modes.
结合线性吸收和非线性三次谐波产生（THG）实验，我们研究了La2CuO4中高度关联电子系统的电子结构细节。我们证明了强THG主要源于从O（2p（σ））到Cu（3d（x2 - y2））的电荷转移激发。THG光谱由于三光子和双光子共振增强以及量子干涉效应而呈现出明显的特征。我们得到了与基于激子簇模型计算的THG光谱的极佳吻合，并能识别出奇偶对称激发模式。
