Enhancing thermoelectric properties of graphene quantum rings

Abstract

We study the thermoelectric properties of rectangular graphene rings connected symmetrically or asymmetrically to the leads. A side-gate voltage applied across the ring allows for the precise control of the electric current flowing through the system. The transmission coefficient of the rings manifests Breit-Wigner line-shapes and/or Fano line-shapes, depending on the connection configuration, the width of nanoribbons forming the ring and the side-gate voltage. We find that the thermopower and the figure of merit are greatly enhanced when the chemical potential is tuned close to resonances. Such enhancement is even more pronounced in the vicinity of Fano like anti-resonances which can be induced by a side-gate voltage independently of the geometry. This opens a possibility to use the proposed device as a tunable thermoelectric generator.

6 pages, 5 figures, accepted for publication in Physical Review B

References in corpus (4)

• The electronic properties of graphene
• Giant thermopower and figure of merit in single-molecule devices
• Optimal thermoelectric figure of merit of a molecular junction
• Interplay of the Aharonov-Bohm effect and Klein tunneling in graphene

Cited by in corpus (7)

• Nanowires: A route to efficient thermoelectric devices
• Thermoelectric efficiency of nanoscale devices in the linear regime
• Spin-dependent heat and thermoelectric currents in a Rashba ring coupled to a photon cavity
• Spin and charge caloritronics in bilayer graphene flakes with magnetic contacts
• Enhanced thermoelectric properties in phosphorene nanorings
• Quantum coherent control of linear and nonlinear thermoelectricity on graphene nanostructure heat engines
• Impact of electron-electron interactions on the thermoelectric efficiency of graphene quantum point contacts