Layered Opposite Rashba Spin-Orbit Coupling in Bilayer Graphene: Loss of Spin Chirality, Symmetry Breaking and Topological Transition

Abstract

Inversion symmetry in bilayer graphene allows for layered opposite Rashba spin-orbit coupling (LO-RSOC) -- the situation when the RSOC has the same magnitude but the opposite sign in two coupled spatially separated layers. We show that the LO-RSOC results in the loss of spin chirality in the momentum space, in contrast to the common uniform RSOC. This chirality loss makes it difficult to experimentally establish whether the LO-RSOC (on the scale of 10 meV) exists, because the band structure is insensitive to it. To solve this problem, we propose to identify the LO-RSOC either by gating to break the inversion symmetry or by magnetic field to break the time-reversal symmetry. Remarkably, we observe the transition between trivial and non-trivial band topology as the system deviates from the LO Rashba state. Ab inito calculations suggest that bilayer graphene encapsulated by two monolayers of Au is a candidate to be a LO Rashba system.

7 pages

References in corpus (16)

• The electronic properties of graphene
• Graphene Spintronics
• The electronic properties of bilayer graphene
• Spin-orbit driven band inversion in bilayer graphene by van der Waals proximity effect
• Uncovering and tailoring hidden Rashba spin-orbit splitting in centrosymmetric crystals
• Quantum Hall Effect Measurement of Spin-Orbit Coupling Strengths in Ultraclean Bilayer Graphene/WSe2 Heterostructures
• Topological phases in gated bilayer graphene: Effects of Rashba spin-orbit coupling and exchange field
• Proximity induced spin orbit effects in graphene on Au
• Bilayer graphene encapsulated within monolayers of WS${}_2$ or Cr${}_2$Ge${}_2$Te${}_6$: Tunable proximity spin-orbit or exchange coupling
• Energy spectrum and Landau levels in bilayer graphene with spin-orbit interaction
• Induced exchange and spin-orbit effects by proximity in graphene on Ni and Co
• Rashba interaction and local magnetic moments in a graphene-Boron Nitride heterostructure by intercalation with Au
• Electrically Controllable van der Waals Antiferromagnetic Spin Valve
• Spin texture in a bilayer high-temperature cuprate superconductor
• Microscopic model for the hidden Rashba effect in YBa${}_2$Cu${}_3$O${}_{6+x}$
• Rigidity of topological invariants to symmetry breakings