Abstract

We construct the holographic dual of an electrically charged localised defect in a conformal field theory at strong coupling. In doing so, we find that the theory sometimes flows to new IR fixed points, some of which we are able to find in a closed form. When the IR theory is either marginally connected to pure AdS, or is AdS itself, we find that a new gravitational phenomena occurs: for an impurity of a sufficiently large amplitude, a spherical extremal Reissner-Nordström black hole nucleates in the domain of outer communications – a hovering black hole. We construct this new phase, for many choices of boundary chemical potential profile, and study its properties. We find a universal curve for the entropy of the defect as a function of its amplitude, reminiscent of an adiabatic Choptuik critical scaling. We comment on the possible field theory implications of our results.