Tunable thermopower in a graphene-based topological insulator

Abstract

Following the recent proposal by Weeks et al., which suggested that indium (or thallium) adatoms deposited on the surface of graphene should turn the latter into a quantum spin Hall (QSH) insulator characterized by a sizeable gap, we perform a systematic study of the transport properties of this system as a function of the density of randomly distributed adatoms. While the samples are, by construction, very disordered, we find that they exhibit an extremely stable QSH phase with no signature of the spatial inhomogeneities of the adatom configuration. We find that a simple rescaling of the spin-orbit coupling parameter allows us to account for the behaviour of the inhomogeneous system using a homogeneous model. This robustness opens the route to a much easier experimental realization of this topological insulator. We additionally find this material to be a very promising candidate for thermopower generation with a target temperature tunable from 1 to 80K and an efficiency ZT close to 1.

7 pages, 5 figures

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Cited by in corpus (15)

• Giant topological insulator gap in graphene with 5d adatoms
• Stabilizing topological phases in graphene via random adsorption
• Giant thermoelectric effect in graphene-based topological insulators with nanopores
• Absence of a transport signature of spin-orbit coupling in graphene with indium adatoms
• Multiple Quantum Phases in Graphene with Enhanced Spin-Orbit Coupling: From the Quantum Spin Hall Regime to the Spin Hall Effect and a Robust Metallic State
• Majorana Fermions in Honeycomb Lattices
• Graphene-based heterojunction between two topological insulators
• Thermoelectric effects in graphene with local spin-orbit interaction
• Coupled Spin and Pseudo-magnetic Field in Graphene Nanoribbons
• Intrinsic and substrate induced spin-orbit interaction in chirally stacked trilayer graphene
• Electronic transport and scattering times in tungsten-decorated graphene
• Bound States and Supercriticality in Graphene-Based Topological Insulators
• Orbital magnetic moments in insulating Dirac systems: Impact on magnetotransport in graphene van der Waals heterostructures
• Competing topological phases in few-layer graphene
• Quasiparticle spectroscopy as a probe of the topological phase in graphene with heavy adatoms