Observation of giant circular dichroism induced by electronic chirality

Autor: Xiao, Qian, Janson, Oleg, Francoual, Sonia, Qiu, Qingzheng, Li, Qizhi, Zhang, Shilong, Xie, Wu, Bereciartua, Pablo, Brink, Jeroen van den, van Wezel, Jasper, Peng, Yingying
Rok vydání: 2023
Předmět:
Zdroj: Phys. Rev. Lett. 133, 126402 (2024)
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevLett.133.126402
Popis: Chiral phases of matter, characterized by a definite handedness, abound in nature, ranging from the crystal structure of quartz to spiraling spin states in helical magnets. In $1T$-TiSe$_2$ a source of chirality has been proposed that stands apart from these classical examples as it arises from combined electronic charge and quantum orbital fluctuations. This may allow its chirality to be accessed and manipulated without imposing either structural or magnetic handedness. However, direct bulk evidence that broken inversion symmetry and chirality are intrinsic to TiSe$_2$ remains elusive. Here, employing resonant elastic scattering of x-rays, we reveal the presence of giant circular dichroism up to $\sim$ 40$\%$ at forbidden Bragg peaks that emerge at the charge and orbital ordering transition. The dichroism varies dramatically with incident energy and azimuthal angle. Comparison to calculated scattering intensities unambiguously traces its origin to bulk chiral electronic order in ${\mathrm{TiSe}}_2$ and establishes resonant elastic x-ray scattering as a sensitive probe to electronic chirality.
Comment: 6 pages, 4 figures
Databáze: arXiv