Year: 2025
Type: article
Abstract: We demonstrate that two-dimensional Kramers-Weyl fermions can be engineered in spin-orbit coupled twisted bilayers, where the chiral structure of these moiré systems breaks all mirror symmetries, confining Kramers-Weyl fermions to high-symmetry points in the Brillouin zone under time reversal symmetry. Our theoretical analysis reveals a symmetry-enforced, Weyl-like spinful interlayer moiré coupling that universally ensures an ideal radial spin-texture at arbitrary twist angles, under C_{nz} symmetry with n>2. First principles density functional calculation confirm the realization of these fermions in twisted α-In_{2}Se_{3} homobilayers, where flat bands and out-of-plane ferroelectric polarization in each layer guarantee two-dimensional Kramers-Weyl physics with ideal radial spin textures.
Source: Physical Review Letters
Authors: D. J. P. de Sousa, Seungjun Lee, Tony Low
Institution: University of Minnesota
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4409802427