Study of in-plane electrical transport anisotropy of a-axis oriented YBa2Cu3O7-δ nanodevices

In the present work, we report the growth of fully untwinned high-quality a-axis-oriented YBa2Cu3O7-δ films on (100) SrLaGaO4 substrates by using PrBa2Cu3O7-δ as a buffer layer. We also fabricated nanowires at different angles γ 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 ξ and London penetration depth λL. Finally, half-integer Shapiro-like steps measured in slightly underdoped c-axis oriented (γ=90°) nanowires point towards a different transport regime, which could shed light on intriguing issues of high-critical-temperature superconductors.