The microwave power handling of a FIB generated weak link in a YBCO film

TL;DR

This study investigates the microwave power handling of a weak link in a YBCO film created by focused ion beam damage, revealing increased resistivity without Josephson behavior up to high rf fields.

Contribution

It provides the first detailed microwave characterization of ion beam damaged weak links in YBCO films, showing their high power resilience and altered electrical properties.

Findings

Damaged region's Tc reduced by 5.5 K

Normal resistivity doubled after ion damage

Weak link exhibits high microwave resistivity without Josephson effects

Abstract

We have measured the power dependent microwave properties of a weak link in a YBa2Cu3O7 thin film formed by writing a line of damage using a focused ion beam. The measurement was made using a parallel plate resonator at 5.5 GHz with the weak link written across the width of one of the plates. The ion induced damage was characterized using a TRIM computer simulation and the dc properties of similar weak links was measured. Using a 200 eV Si ion dose of 2e13 cm-2, the Tc of the damaged region was reduced by 5.5 K and the normal resistivity was doubled. Surprisingly, the microwave measurements did not show any Josephson junction characteristics. Rather, the ion damaged region exhibited a greatly increased microwave resistivity that was constant as a function of microwave power up to rf fields of 20 mT at 21 K.