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

L Fang,Y Jia,A Glatz,J Im,W Degottardi,K A Matveev,M G Kanatzidis,G W Crabtree,W-K Kwok

doi:10.1038/srep35313

Abstract

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 [Pb2BiS3][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 εso = 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.

Highlights

The motion of an electron through a lattice potential gives rise to a coupling between the electron’s momentum and its spin
spin-orbit coupling (SOC) manifests itself in quantum interference phenomena such as weak antilocalization (WAL)[17,18]
In the diffusion regime and in the case of self-intersecting electron scattering paths, the interference between the electron’s time reversed paths is pronounced and tends to localize electrons. This phenomenon is known as weak localization (WL)

Summary

Introduction

The motion of an electron through a lattice potential gives rise to a coupling between the electron’s momentum and its spin. More emergent properties can be expected in similar systems with sufficiently strong SOC such as naturally formed crystalline heterostructures that adopt a structure similar to those of epitaxially grown heterostructure films. A strong advantage of naturally formed heterostructures is that a large number of organic and inorganic materials adopt this type of structure, for example the intergrowth chalcogenides[12] and the inorganic-organic hybrid systems such as halides[13]. These crystal heterostructures provide a parallel platform to epitaxial films to uncover novel quantum phenomena derived from strong SOC and inversion symmetry breaking[10,11]. The helical-like spin textures could be an effect arising from the strong SOC and the unique heterostructure in [Pb2BiS3][AuTe2]

Methods

Results

Conclusion