Rayleigh-Taylor instability in binary condensates

We propose a well-controlled experimental scheme to initiate and examine the Rayleigh-Taylor instability in two-species Bose-Einstein condensates. We identify the Rb-85-Rb-87 mixture as an excellent candidate to observe experimentally. The instability is initiated by tuning the Rb-85-Rb-85 interaction through a magnetic Feshbach resonance. We show that the observable signature of the instability is the damping of the radial oscillations. We also propose a semianalytic scheme to determine the stationary state of binary condensates with the Thomas-Fermi approximation for axisymmetric traps.