Self-similar turbulence-like dynamics in a quasi-ideal Bose gas

We study the dynamics of an essentially non-interacting Bose gas under strong periodic forcing. We initially prepare a quasi-pure BEC in a cylindrical optical box trap and then tune the s-wave scattering length to zero, before violently injecting energy into the system using a time-periodic spatially uniform force oriented along the box axis. We observe a rapid excitation of the initially accessible axial eigenstates, followed by a gradual leakage of energy into the (orthogonal) radial directions. The later-time momentum-resolved dynamics exhibit self-similar scaling behavior, surprisingly reminiscent of the turbulent cascade dynamics in an interacting gas, but with stark quantitative differences in the scaling exponents describing the dynamics. The non-equilibrium samples prepared in this way also provide interesting initial conditions for testing universality in the relaxation dynamics of isolated Bose gases far from equilibrium.