Year: 2010
Type: article
Abstract: We discovered the chirality of charge-density waves (CDW) in $1T\mathrm{\text{\ensuremath{-}}}{\mathrm{TiSe}}_{2}$ by using STM and time-domain optical polarimetry. We found that the CDW intensity becomes $I{a}_{1}\ensuremath{\mathbin:}I{a}_{2}\ensuremath{\mathbin:}I{a}_{3}=1\ensuremath{\mathbin:}0.7\ifmmode\pm\else\textpm\fi{}0.1\ensuremath{\mathbin:}0.5\ifmmode\pm\else\textpm\fi{}0.1$, where $I{a}_{i}$ ($i=1,2,3$) is the amplitude of the tunneling current contributed by the CDWs. There were two states, in which the three intensity peaks of the CDW decrease clockwise and anticlockwise. The chirality in CDW results in the threefold symmetry breaking. Macroscopically, twofold symmetry was indeed observed in optical measurement. We propose the new generalized CDW chirality ${H}_{\mathrm{CDW}}\ensuremath{\equiv}{\mathbit{q}}_{\mathbf{1}}\ifmmode\cdot\else\textperiodcentered\fi{}({\mathbit{q}}_{\mathbf{2}}\ifmmode\times\else\texttimes\fi{}{\mathbit{q}}_{\mathbf{3}})$, where ${\mathbit{q}}_{\mathbit{i}}$ are the CDW $q$ vectors, which is independent of the symmetry of components. The nonzero ${H}_{\mathrm{CDW}}$---the triple-$q$ vectors do not exist in an identical plane in the reciprocal space---should induce a real-space chirality in CDW system.
Source: Physical Review Letters
Authors: J. Ishioka, Y. H. Liu, K. Shimatake, T. Kurosawa, K. Ichimura, Y. Toda, M. Oda, S. Tanda
Institution: Hokkaido University
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2079267382