As an intermediate state in the topological phase diagram, Dirac semimetals are of particular interest as a platform for studying topological phase transitions under external modulations. Despite a growing theoretical interest in this topic, it remains a substantial challenge to experimentally tune the system across topological phase transitions. Here, we investigate the Fermi surface evolution of Cd3As2 under high pressure through magnetotransport. A sudden change in Berry phase occurs at 1.3 GPa along with the unanticipated shrinkage of the Fermi surface, which occurs well below the structure transition point (~2.5 GPa). High pressure X-ray diffraction also reveals an anisotropic compression of the Cd3As2 lattice around a similar pressure. Corroborated by the first-principles calculations we show that an axial compression will shift the Dirac nodes towards the Brillouin zone center and eventually introduces a finite energy gap. The ability to tune the node position, a vital parameter of Dirac semimetals, can have dramatic impacts on the corresponding topological properties such as the Fermi arc surface states and the chiral anomaly. Our study demonstrates axial compression as an efficient approach for manipulating the band topology and exploring the critical phenomena near the topological phase transition in Cd3As2.
@article{arxiv.1612.05874,
title = {Evidence for pressure-induced node-pair annihilation in Cd3As2},
author = {Cheng Zhang and Jianping Sun and Fengliang Liu and Awadhesh Narayan and Nana Li and Xiang Yuan and Yanwen Liu and Jianhong Dai and Youwen Long and Yoshiya Uwatoko and Jian Shen and Stefano Sanvito and Wenge Yang and Jinguang Cheng and Faxian Xiu},
journal= {arXiv preprint arXiv:1612.05874},
year = {2017}
}