A rotating bucket experiment with Bose-Einstein condensate

Quantized vortices, found in rotating liquid helium, quantum gases, and Type-II superconductors, have attracted ongoing attention from across mathematics and physics. An extraordinarily rich phase diagram for quantum vortex matter has been proposed, exhibiting for instance lattice, liquid, glass, and phases. Especially in the lowest Landau level, the positions of vortices realize complex zeros of random polynomials. Here we report the realization of a "rotating bucket" experiment using a rapidly-rotating Bose-Einstein condensate confined by a cylindrical optical wall potential. Upon balancing the centrifugal force and underlying trapping force in the rotating frame, the condensate exhibits a flat density profile and a proliferation of quantum vortices in its bulk. We experimentally realize a homogeneous, isotropic vortex liquid phase, demonstrate that the vortex density fully satisfies the Feynman’s criterion, and show intriguing statistics in the vortex-vortex correlations originated from their pair-wise interaction.