Protecting entanglement from finite-temperature thermal noise via weak measurement and quantum measurement reversal
Wenjie Zou, Yu-Huai Li, Shuchao Wang, Yuan Wen Cao, Ji-Gang Ren, Juan Yin, Cheng-Zhi Peng, Xiang‐Bin Wang, Jian-Wei Pan · Physical Review A · 2017
In practical applications, quantum systems work in a finite-temperature environment. Quantum entanglement is inevitably destroyed by the thermal noise. Here we experimentally demonstrate the protection of entanglement on the platform of linear optics. The finite-temperature thermal noise is described by the generalized amplitude-damping channel. By performing optimal pre- and postchannel weak measurements, we successfully protect the entanglement from the generalized amplitude-damping channel. Compared with the unprotected case, the quantum coherence is recovered, and the entanglement is enhanced. The demonstrated protocol may have further applications in superconducting quantum qubits.