Lehrstuhl für Theoretische Physik, Universität Paderborn, Paderborn, Germany.
IEEE Trans Ultrason Ferroelectr Freq Control. 2012 Sep;59(9):1929-33. doi: 10.1109/TUFFC.2012.2409.
The dielectric function and second-harmonic generation spectrum of ferroelectric LiNbO(3) are calculated from first principles. The calculations are based on the electronic structure obtained within density functional theory. The use of the GW approach to account for quasiparticle effects and the subsequent solution of the Bethe-Salpeter equation lead to a dielectric function in excellent agreement with measured data. The second harmonic generation spectrum calculated within the independent (quasi) particle approximation predicts strong nonlinear coefficients for photon energies above about 1.5 eV. The comparison with measured data suggests that the inclusion of self-energy effects in the nonlinear response improves the agreement with experiment.
从第一性原理出发，计算了铁电 LiNbO(3) 的介电函数和二次谐波产生光谱。计算基于密度泛函理论获得的电子结构。使用 GW 方法来考虑准粒子效应，并随后求解 Bethe-Salpeter 方程，得到了与测量数据非常吻合的介电函数。在独立（准）粒子近似下计算的二次谐波产生光谱预测，在大约 1.5 eV 以上的光子能量下具有很强的非线性系数。与实验数据的比较表明，在非线性响应中包含自能效应可以提高与实验的一致性。
