  We investigate the minimum entanglement cost of the deterministic
implementation of two-qubit controlled-unitary operations using local
operations and classical communication (LOCC). We show that any such operation
can be implemented by a three-turn LOCC protocol, which requires at least 1
ebit of entanglement when the resource is given by a bipartite entangled state
with Schmidt number 2. Our result implies that there is a gap between the
minimum entanglement cost and the entangling power of controlled-unitary
operations. This gap arises due to the requirement of implementing the
operations while oblivious to the identity of the inputs.
