Hot spot formation in focused-ion-beam-fabricated YBa₂Cu₃O_7−x nanobridges with high critical current densities

Abstract

We report on the fabrication and evaluation of nanoscale YBa 2 Cu 3 O 7−x (YBCO) constrictions using focused-ion-beam techniques for potential application as YBCO bolometers. A gold protective layer was found to be critical for supressing contamination from gallium ions in order to obtain high critical current densities. Further processing using a radio-frequency plasma to remove the gold protective layer has also been studied and was found to be effective in minimizing sample damage resulting from overheating. Current-voltage measurement indicate that the nanobridges go through the transition from superconducting to normal state with different dissipation mechanism including flux creep and hot spot formation.

Fabrication and electrical transport characterization of high quality underdoped YBa2Cu3O7-δ nanowires

“…It is by now well established that the complex phase diagram of HTS is dominated by various local electronic orders that are intertwined with superconductivity and become stronger in the underdoped region of the phase diagram [1]. All recent activities on HTS nanowires are focused on optimal doping [2][3][4][5][6][7][8][9][10]. The realization of underdoped nanowires with dimensions comparable to the relevant length scales of the Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence.…”