论文标题
钛酸盐质质和结构相变超过密度功能理论
Quantum paraelectricity and structural phase transitions in strontium titanate beyond density-functional theory
论文作者
论文摘要
我们展示了一种计算温度依赖性量子和非谐作用的方法，具有超过密度功能的理论精度。通过将机器学习电位和随机自洽的谐波近似相结合，我们研究了钛酸锶中的四方向四方转变，并表明副阶段通过非谐波量子波动稳定。我们发现，对量子副行为的定量理解需要通过随机相近似对电子相关效应进行更高级别的处理。这种方法可以详细研究超出密度功能理论的强烈肛门材料中的新兴特性。
We demonstrate an approach for calculating temperature-dependent quantum and anharmonic effects with beyond density-functional theory accuracy. By combining machine-learned potentials and the stochastic self-consistent harmonic approximation, we investigate the cubic to tetragonal transition in strontium titanate and show that the paraelectric phase is stabilized by anharmonic quantum fluctuations. We find that a quantitative understanding of the quantum paraelectric behavior requires a higher-level treatment of electronic correlation effects via the random phase approximation. This approach enables detailed studies of emergent properties in strongly anharmonic materials beyond density-functional theory.
