Spectra of the third-order nonlinear susceptibility χ⁽³⁾ have been investigated for one-dimensional Mott insulators, Sr₂CuO₃ and Ca₂CuO₃, by applying the third-harmonic generation (THG) spectroscopy on their single-crystalline thin films. The three-photon resonance to the lowest charge-transfer (CT) state with odd parity strongly enhances χ⁽³⁾, which is of the order of 10^-90ex0exesu. The two-photon resonant structure unravels the even-CT state, located close to the odd-CT state. Two types of χ⁽³⁾ spectra obtained from THG and the electroreflectance measurements are explained based on the concept of spin-charge separation.
No takes yet. Share an insight, caveat, or question.
Kishida et al. (2001) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: