Impurity pinning has long been discussed to have a profound effect on the dynamics of an incommensurate charge density wave (CDW), which would otherwise slide through the lattice without resistance. Here we visualize the impurity pinning evolution of the CDW in ZrTe3 using the variable temperature scanning tunneling microscopy (STM). At low temperatures, we observe a quasi-1D incommensurate CDW modulation moderately correlated to the impurity positions, indicating a weak impurity pinning. As we raise the sample temperature, the CDW modulation gets progressively weakened and distorted, while the correlation with the impurities becomes stronger. Above the CDW transition temperature, short-range modulations persist with the phase almost all pinned by impurities. The evolution from weak to strong impurity pinning through the CDW transition can be understood as a result of losing phase rigidity.
@article{arxiv.2105.02640,
title = {Thermal dynamics of charge density wave pinning in ZrTe3},
author = {Limin Liu and Changjiang Zhu and Z. Y. Liu and Hanbin Deng and X. B. Zhou and Yuan Li and Yingkai Sun and Xiong Huang and Shuaishuai Li and Xin Du and Zheng Wang and Tong Guan and Hanqing Mao and Y. Sui and Rui Wu and Jia-Xin Yin and J. -G. Cheng and Shuheng H. Pan},
journal= {arXiv preprint arXiv:2105.02640},
year = {2021}
}