Josephson vortex dynamics in Bi2Sr2CaCu2O8+δ intrinsic Josephson junctions under high magnetic field

Abstract We have investigated vortex dynamics in Bi 2 Sr 2 CaCu 2 O 8 intrinsic Josephson junctions subjected to magnetic field parallel and perpendicular to the CuO 2 planes. We measured mesas with 40 × 40 μm 2 in size containing ∼20 intrinsic junctions. The zero field I–V characteristics showed typical hysteretic, multi-branched nature of the intrinsic Josephson effect. In high parallel magnetic field (H > 1.5 T), I–V characteristics showed the flux flow step. The step voltage agreed well with the value estimated from known junction parameters. The obtained Swihart velocity was about 4.2 × 10 5 m/s, which corresponds to the velocity of the lowest mode electromagnetic wave of N -coupled stack. The Experimental I–V curves fit well to the model of Cherenkov radiation including Ohmic and non-linear dissipation terms.