Study of in-plane electrical transport anisotropy of a-axis oriented YBa_2Cu_3O_(7-δ) nanodevices

摘要

In the present work, we report the growth of fully untwinned high-quality a-axis-oriented YBa_2Cu_3O_(7-δ) films on (100) SrLaGaO_4 substrates by using PrBa_2Cu_3O_(7-δ) as a buffer layer. We also fabricated nanowires at different angles y with respect to the [0,1,0] direction of the substrate and studied the in-plane anisotropy of the critical current density, which we explained by considering the anisotropy in the coherence length ζ and London penetration depth λ_L. Finally, half-integer Shapiro-like steps measured in slightly underdoped c-axis oriented (y = 90°) nanowires point towards a different transport regime, which could shed light on intriguing issues of high-critical-temperature superconductors.