Quantum turbulence (QT) generated by the Rayleigh-Taylor instability in
binary immiscible ultracold 87Rb atoms at zero temperature is studied
theoretically. We show that the quantum vortex tangle is qualitatively
different from previously considered superfluids, which reveals deep relations
between QT and classical turbulence. The present QT may be generated at
arbitrarily small Mach numbers, which is a unique property not found in
previously studied superfluids. By numerical solution of the coupled
Gross-Pitaevskii equations we find that the Kolmogorov scaling law holds for
the incompressible kinetic energy. We demonstrate that the phenomenon may be
observed in the laboratory.Comment: Revised version. 7 pages, 8 figure
