Coherent quasiparticle transport in grain boundary junctions employing high-Tc superconductors

TL;DR

This paper investigates mesoscopic quasiparticle transport in high-temperature superconductor grain boundary junctions, revealing magneto-fluctuations linked to the Thouless energy, which enhances understanding of coherence and dissipation in these systems.

Contribution

It demonstrates the role of the Thouless energy in mesoscopic transport phenomena in high-Tc superconductor grain boundary junctions, providing new insights into quasiparticle coherence.

Findings

Reproducible magneto-fluctuations observed in resistance

Identification of the Thouless energy as key energy scale

Implications for understanding quasiparticle coherence and dissipation

Abstract

Magneto-fluctuations of the normal resistance RN have been reproducibly observed in YBa2Cu3O7-d biepitaxial grain boundary junctions at low temperatures. We attribute them to mesoscopic transport in narrow channels across the grain boundary line, occurring in an unusual energy regime. The Thouless energy appears to be the relevant energy scale. Possible implications on the understanding of coherent transport of quasiparticles in HTS and of the dissipation mechanisms are discussed.