Observation of polarization density waves in SrTiO3
Abstract
The nature of the "failed" ferroelectric transition in SrTiO3 has been a long-standing puzzle in condensed matter physics. A compelling explanation is the competition between ferroelectricity and an instability with a mesoscopic modulation of the polarization. These polarization density waves, which should become especially strong near the quantum critical point, break local inversion symmetry and are difficult to probe with conventional x-ray scattering methods. Here we combine a femtosecond x-ray free electron laser (XFEL) with THz coherent control methods to probe inversion symmetry breaking at finite momenta and visualize the instability of the polarization on nanometer lengthscales in SrTiO3. We find polar-acoustic collective modes that are soft particularly at the tens of nanometer lengthscale. These precursor collective excitations provide evidence for the conjectured mesoscopic modulated phase in SrTiO3.
Keywords
Cite
@article{arxiv.2403.17203,
title = {Observation of polarization density waves in SrTiO3},
author = {Gal Orenstein and Viktor Krapivin and Yijing Huang and Zhuquan Zhan and Gilberto de la Pena Munoz and Ryan A. Duncan and Quynh Nguyen and Jade Stanton and Samuel Teitelbaum and Hasan Yavas and Takahiro Sato and Matthias C. Hoffmann and Patrick Kramer and Jiahao Zhang and Andrea Cavalleri and Riccardo Comin and Mark P. M. Dean and Ankit S. Disa and Michael Forst and Steven L. Johnson and Matteo Mitrano and Andrew M. Rappe and David Reis and Diling Zhu and Keith A. Nelson and Mariano Trigo},
journal= {arXiv preprint arXiv:2403.17203},
year = {2024}
}