Topological Signatures in the Electronic Structure of Graphene Spirals

TL;DR

This paper introduces graphene spirals with unique topological properties, revealing intrinsic Rashba spin-orbit splitting and topologically protected states, and discusses their feasible synthesis methods.

Contribution

It presents a novel topological form of graphene, analyzes their electronic properties using density-functional theory, and proposes experimental synthesis routes.

Findings

Graphene spirals exhibit intrinsic Rashba spin-orbit splitting.

Topologically protected states are present due to curvature and time-reversal symmetry.

Synthesis of graphene spirals is experimentally feasible.

Abstract

Topology is familiar mostly from mathematics, but also natural sciences have found its concepts useful. Those concepts have been used to explain several natural phenomena in biology and physics, and they are particularly relevant for the electronic structure description of topological insulators and graphene systems. Here, we introduce topologically distinct graphene forms - graphene spirals - and employ density-functional theory to investigate their geometric and electronic properties. We found that the spiral topology gives rise to an intrinsic Rashba spin-orbit splitting. Through a Hamiltonian constrained by space curvature, graphene spirals have topologically protected states due to time-reversal symmetry. In addition, we argue that the synthesis of such graphene spirals is feasible and can be achieved through advanced bottom-up experimental routes that we indicate in this work.