Instability crossover of helical shear flow in segregated Bose-Einstein condensates
Shinsuke Hayashi, Makoto Tsubota, Hiromitsu Takeuchi
We theoretically study the instability of helical shear flows, in which one fluid component flows along the vortex core of the other, in phase-separated two-component Bose-Einstein condensates at zero temperature. The helical shear flows are hydrodynamically classified into two regimes: (1) a helical vortex sheet, where the vorticity is localized on the cylindrical interface and the stability is described by an effective theory for ripple modes, and (2) a core-flow vortex with the vorticity distributed in the vicinity of the vortex core, where the instability phenomena are dominated only by the vortex-characteristic modes (Kelvin and varicose modes). The helical shear-flow instability shows remarkable competition among different types of instabilities in the crossover regime between the two regimes.
arXiv:1304.5143•Physical Review A•Jun 24, 2013•25 citations