Coherent activation of a steerability-breaking channel

The inevitable noise within one-sided device-independent quantum information tasks may completely break any steering resources. These noisy effects are characterized by the steerability breaking (SB) channels. In this work, we demonstrate the use of a control system that can superpose N copies of the given SB channel to activate SB channels such that the channel becomes a non-SB one. In particular, we analytically and numerically show that the SB depolarizing and amplitude-damping channel can be coherently activated when N≥2. In addition, for both cases, the channels can preserve more steerability when increasing N. Finally, we propose circuit models to implement our proposed approaches and present the simulation results.