Periodic Oscillations of Josephson-Vortex Flow Resistance inBi2Sr2Ca

Abstract

To study the Josephson-vortex system, we have measured the vortex-flow resistance as a function of magnetic field parallel to the ab plane in Bi(2)Sr(2)CaCu(2)O(8+y) single crystals. Novel periodic oscillations of the vortex-flow resistance have been observed in a wide range of temperatures and magnetic fields. The period of the oscillations corresponds to the field needed to add "one" vortex quantum per "two" intrinsic Josephson junctions. The flow velocity is related to a matching effect between the lattice spacing of Josephson vortices along the layers and the width of the sample. These results suggest that Josephson vortices form a triangular lattice in the ground state where the oscillations occur.

Origin of flux-flow resistance oscillations inBi2Sr2CaCu2O8+y

“…Promising experiments in that direction were reported by Hirata et al 2 and shortly thereafter by Kakeya et al 3 and Hatano et al 4 These experiments all showed oscillations in the flux-flow voltage and flux-flow resistance when a large magnetic field ͑of order several Tesla͒ was applied parallel to the ab plane in the presence of a small bias current in the c-direction ͑of order a few percent of the critical current͒. The observed flux-flow voltage oscillations typically showed two different oscillation periods.…”

Josephson-Vortex-Flow Terahertz Emission in Layered High-TcSuperconducting Single Crystals

“…Figs . The H 0 /2 JVFR oscillation, often observed in the S-shaped embedded structures, is known to originate from the interaction between a triangular vortex lattice and the edge potential for the vortex entry and exit at the junction boundaries [12,13]. The H 0 /2 oscillation in our sandwiched oscillator stack thus strongly indicates the formation of the triangular lattice in its low-bias static limit.…”

Numerical simulations of flux flow in stacked Josephson junctions

“…Recently, the dynamic properties of this lattice in BSCCO have been the subject of extensive experimental research. [7][8][9] Quite typically, magnetic field oscillations of the flux flow voltage or the flux flow resistance with either a ⌽ 0 or a ⌽ 0 / 2 periodicity ͑in applied field times the layer area͒ has been observed. A straightforward explanation of such periodicities can be obtained by looking at the lattice structure.…”