Preparation of hybrid Josephson junctions on Co-doped Ba-122 single crystals

Abstract

Abstract. In this paper we present a method for processing a hybrid Josephson junction on Co-doped BaFe 2 As 2 (Ba-122) single crystals with a thin film Pb-counter electrode and a barrier layer of TiO x . This includes the leveling and polishing of the crystals and structuring them with thin film techniques such as photo lithography, sputtering and ion beam etching (IBE). The junctions show hysteretical resistively and capacitively shunted junction (RCSJ)-like I-V characteristics with an I c R n -product of about 800 µV. ‡ Present address: Physikalisch-Technische Bundesanstalt (PTB),

Josephson effects at iron pnictide superconductors: Approaching phase‐sensitive experiments

“…The details for the polishing procedure for single crystals can be found in Ref. . Another important step for both thin film and single crystal samples is the covering of the whole surface crystals with gold to avoid degradation during future photolithography processes.…”

Normal-state and superconducting properties of Co-doped BaFe2As2 and MgB2 thin films after focused helium ion beam irradiation

“…Besides, 122 compounds have small anisotropy and relatively high-T c opening the way for possible application. In spite of pioneer works on Josephson junctions and SQUID device using grain boundaries [3,4] and heterojunctions [5,6] of 122 family, achieving reproducible high-quality JJs remains a challenge.…”

Ultrafast dynamics of quasiparticles and coherent acoustic phonons in slightly underdoped (BaK)Fe2As2

“…Compounds of the 122 system are the easiest among the iron-based superconductors to synthesize in the form of large single crystals, and most publications have been devoted to 122 compounds2. Because superconductor-based devices require high quality crystals/films, the 122 system has also been employed most often among the iron-based compounds to demonstrate devices such as Josephson junctions3456 and superconducting wires/tapes for high current applications78910111213141516. Although the unconventional high-temperature superconductors (including copper-based and iron-based superconductors) have been applied for devices, the fundamental questions such as the forming mechanisms of Cooper pairs remain unclear17.…”