Coherent activation of a steerability-breaking channel
Huan-Yu Ku, Kuan-Yi Lee, Po-Rong Lai, Jhen-Dong Lin, Yueh-Nan Chen · Physical Review A · 2023
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 $N\ensuremath{\ge}2$. 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.