Thermal and electrical transport at nanosized metallic contacts: In the diffusive-ballistic region at room temperature

The Wiedemann-Franz law has been proved at the quantized metallic contacts but has never been verified at the nanosized contacts when the electrons travel in the diffusive-ballistic region. Herein, by developing a home-made inelastic tunneling spectroscope, the electrical and thermal resistances of the nanosized metallic contacts are investigated. The contact is established by pressing two wires crosswise against each other under the Lorentz force in the magnetic field. The nonmetallic surface layer is in situ removed by the resistive heating under high vacuum. The temperature dependence of the electrical contact resistance is used to separate the contributions from the diffusive and the ballistic transports. The thermal contact resistance is found to increase linearly with the electrical counterpart, indicating the validity of the Wiedemann-Franz law at the clean metallic contacts.

Automated summary

A homemade inelastic tunneling spectroscope was used to investigate the electrical and thermal resistances of nanosized metallic contacts established by Lorentz force pressing two wires crosswise in a magnetic field. The study found that the thermal contact resistance increases linearly with the electrical counterpart, indicating the validity of the Wiedemann-Franz law at clean metallic contacts.