  Realization of indefinite causal order (ICO), a theoretical possibility that
even causal relations between physical events can be subjected to quantum
superposition, apart from its general significance for the fundamental physics
research, would also enable quantum information processing that outperforms
protocols in which the underlying causal structure is definite. In this paper,
we start with a proposition that an observer in a state of quantum
superposition of being at two different relative distances from the event
horizon of a black hole, effectively resides in ICO space-time generated by the
black hole. By invoking the fact that the near-horizon geometry of a
Schwarzschild black hole is that of a Rindler space-time, we propose a way to
simulate an observer in ICO space-time by a Rindler observer in a state of
superposition of having two different proper accelerations. By extension, a
pair of Rindler observers with entangled proper accelerations simulates a pair
of entangled ICO observers. Moreover, these Rindler-systems might have a
plausible experimental realization by means of optomechanical resonators.
