Seebeck effect at the atomic scale

Abstract

The atomic variations of electronic wavefunctions at the surface and electron scattering near a defect have been detected unprecedentedly by tracing thermoelectric voltages given a temperature bias [Cho et al., Nature Mater. 12, 913 (2013)]. Because thermoelectricity, or Seebeck effect, is associated with heat-induced electron diffusion, how the thermoelectric signal is related to the atomic-scale wavefunctions and what the role of the temperature is at such a length scale remain very unclear. Here we show that coherent electron and heat transport through a point-like contact produces an atomic Seebeck effect, which is described by mesoscopic Seebeck coefficient multiplied with an effective temperature drop at the interface. The mesoscopic Seebeck coefficient is approximately proportional to the logarithmic energy derivative of local density of states at the Fermi energy. We deduced that the effective temperature drop at the tip-sample junction could vary at a sub-angstrom scale depending on atom-to-atom interaction at the interface. A computer-based simulation method of thermoelectric images is proposed, and a point defect in graphene was identified by comparing experiment and the simulation of thermoelectric imaging.

Main text (16 pages including 4 figures and 34 references) plus Supplementary Information (10 pages including 6 figures)

References in corpus (4)

• Thermoelectric and Magnetothermoelectric Transport Measurements of Graphene
• Origins of anomalous electronic structures of epitaxial graphene on silicon carbide
• Heat Conduction across Monolayer and Few-Layer Graphenes
• Thermoelectric imaging of structural disorder in epitaxial graphene

Cited by in corpus (10)

• Efficiency fluctuations in quantum thermoelectric devices
• Electron transfer across a thermal gradient
• Photothermoelectric effects and large photovoltages in plasmonic Au nanowires with nanogaps
• Derivation of a governing rule in triboelectric charging and series from thermoelectricity
• Electron transfer at thermally heterogeneous molecule-metal interfaces
• DC Electric Fields in Electrode-Free Glass Vapor Cell by Photoillumination
• Molecular Heat Engines: Quantum Coherence Effects
• Controlling the thermoelectric effect by mechanical manipulation of the electron's quantum phase in atomic junctions
• Electron hopping heat transport in molecules
• Intrinsic nonlinear Nernst and Seebeck effect