Large spin-orbit coupling and helical spin textures in 2D heterostructure [Pb₂BiS₃[[AuTe₂]]

Two-dimensional heterostructures with strong spin-orbit coupling have direct relevance to topological quantum materials and potential applications in spin-orbitronics. In this work, we report on novel quantum phenomena in [Pb₂ BiS₃[[AuTe₂[, a new 2D strong spin-orbit coupling heterostructure system. Transport measurements reveal the spin-related carrier scattering is at odds with the Abrikosov-Gorkov model due to strong spin-orbit coupling. This is consistent with our band structure calculations which reveal a large spin-orbit coupling gap of e_so so = 0.21 eV. The band structure is also characterized by helical-like spin textures which are mainly induced by strong spin-orbit coupling and the inversion symmetry breaking in the heterostructure system.