  We study the canonical purification (with respect to one of the parties) of
pure, bi-partite states obtained by turning on sources in the Euclidean path
integral. In holographic conformal field theories, the Lorentzian bulk dual of
the canonical purification consists of the corresponding entanglement wedge
glued to its CPT image at the quantum extremal surface. However, the mismatch
in the classical expansions at the QES due to quantum corrections needs to be
supported by a shock in the bulk matter stress tensor in order for the bulk to
satisfy Einstein's equations. Working perturbatively to first order in
double-trace sources around the thermofield double state, we demonstrate that
the state of the bulk matter in the dual to the canonically purified boundary
CFT state precisely has this quantum extremal shock in the bulk stress tensor.
We interpret our results as the emergence of gravitational physics from the CFT
entanglement structure in a context where bulk quantum corrections are
important.
