Intrinsic Josephson junctions in the iron-based multi-band superconductor (V2Sr4O6)Fe2As2

Abstract

In layered superconductors, Josephson junctions may be formed within the unit cell due to sufficiently low interlayer coupling. These intrinsic Josephson junction (iJJ) systems have attracted considerable interest for their application potential in quantum computing as well as efficient sources of THz radiation, closing the famous "THz gap". So far, iJJ have been demonstrated in single-band, copper-based high-Tc superconductors, mainly in Ba-Sr-Ca-Cu-O. Here we report clear experimental evidence for iJJ behavior in the iron-based superconductor (V2Sr4O6)Fe2As2. The intrinsic junctions are identified by periodic oscillations of the flux flow voltage upon increasing a well aligned in-plane magnetic field. The periodicity is well explained by commensurability effects between the Josephson vortex lattice and the crystal structure, which is a hallmark signature of Josephson vortices confined into iJJ stacks. This finding adds (V2Sr4O6)Fe2As2 as the first iron-based, multi-band superconductor to the copper-based iJJ materials of interest for Josephson junction applications, and in particular novel devices based on multi-band Josephson coupling may be realized.

Accepted in Nature Physics

References in corpus (4)

• Macroscopic quantum tunneling in a d-wave high-Tc superconductor
• High magnetic field scales and critical currents in SmFeAs(O,F) crystals: promising for applications
• Periodic Oscillations of Josephson-Vortex Flow Resistance in Oxygen-Deficient Y1Ba2Cu3Ox
• In-plane current-voltage characteristics and oscillatory Josephson-vortex flow resistance in La-free Bi${}_{2+x}$Sr${}_{2-x}$CuO${}_{6+\delta }$ single crystals in high magnetic fields

Cited by in corpus (7)

• Reentrant Phase Coherence in Superconducting Nanowire Composites
• Quasi two-dimensional nature of high-Tc superconductivity in iron-based (Li,Fe)OHFeSe
• Deviation from canonical collective creep behavior in Li${}_{0.8}$Fe${}_{0.2}$OHFeSe
• Critical current oscillations in the intrinsic hybrid vortex state of SmFeAs(O,F)
• Upper critical field, pressure-dependent superconductivity and electronic anisotropy of Sm${}_4$Fe${}_2$As${}_2$Te${}_{1-x}$O${}_{4-y}$F$y$
• In-plane magnetic field vs. temperature phase diagram of a quasi-2D frustrated multiband superconductor
• Edge currents in frustrated Josephson junction ladders