  We propose an experimental method for extracting the zero-point energy from a
local vacuum state by performing local operations and classical communication
(LOCC). We model a quantum Hall edge channel as a quantum entangled many-body
channel and the zero-point fluctuation in the charge density of the channel as
the vacuum state. We estimate the order of the energy gain using reasonable
experimental parameters. Such a quantum feedback system breaks the passivity of
a local vacuum state. It can be used to demonstrate Maxwell's demon or quantum
energy teleportation in which no physical entity transports energy.
