5 research outputs found
Binary Quantum Turbulence Arising from Countersuperflow Instability in Two-Component Bose-Einstein Condensates
We theoretically study the development of quantum turbulence from two
counter-propagating superfluids of miscible Bose-Einstein condensates by
numerically solving the coupled Gross-Pitaevskii equations. When the relative
velocity exceeds a critical value, the counter-superflow becomes unstable and
quantized vortices are nucleated, which leads to isotropic quantum turbulence
consisting of two superflows. It is shown that the binary turbulence can be
realized experimentally in a trapped system.Comment: 5 pages, 3 figure
Countersuperflow instability in miscible two-component Bose-Einstein condensates
We study theoretically the instability of countersuperflow, i.e., two
counterpropagating miscible superflows, in uniform two-component Bose-Einstein
condensates. Countersuperflow instability causes mutual friction between the
superfluids, causing a momentum exchange between the two condensates, when the
relative velocity of the counterflow exceeds a critical value. The momentum
exchange leads to nucleation of vortex rings from characteristic density
patterns due to the nonlinear development of the instability. Expansion of the
vortex rings drastically accelerates the momentum exchange, leading to a highly
nonlinear regime caused by intervortex interaction and vortex reconnection
between the rings. For a sufficiently large interaction between the two
components, rapid expansion of the vortex rings causes isotropic turbulence and
the global relative motion of the two condensates relaxes. The maximum vortex
line density in the turbulence is proportional to the square of the relative
velocity.Comment: 9 pages, 6 figure