2024/01/03 by Hyeonjung Kim, Kim, Hyeonjung, Kyung‐Hwan Jin +3 · 1 citation
Engineering · Materials Science · #2D Materials and Applications #Advanced Thermoelectric Materials and Devices #Chalcogenide Semiconductor Thin Films #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Strongly Correlated Electrons (cond-mat.str-el)
paper · pdf · doi:10.48550/arxiv.2401.01669
openalex publication_date 2024/01/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Chiral charge density wave (CDW) is widely observed in low dimensional systems to be entangled with various emerging phases but its microscopic origin has been elusive. We reinvestigate the representative but debated chiral CDW of TiSe2 using scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. Our STM data reveal unambiguously the chiral distortion of the topmost Se layer in domains of opposite chirality, which are interfaced with a novel domain wall. DFT calculations find the atomic structure of the chiral CDW, which has a C2 symmetry with the inversion and reflection symmetry broken. The chirality is determined by the helicity of Se-Ti bond distortions and their translation between neighboring layers. The present structure reproduces well the STM images with lower energy than the prevailing non-chiral P3c1 structure model. Our result provides the atomistic understanding of the CDW chirality in TiSe2, which can be referred to in a wide class of monolayer and layered materials with CDW.