Quantum Entanglement Protection by Utilizing Classical Noises

Abstract

AbstractNoise is often considered as the biggest enemy of maintaining quantum entanglement. However, in this paper, it shows quantum entanglement can be protected by introducing extra noises to a quantum system. As an example, the dynamics of a two‐qubit system coupled to a cavity is studied under the influence of three noises, a quantized noise from the leakage of the cavity and two classical noises in the couplings between the two‐qubit system and the cavity. The master equation beyond the Markov approximation is derived and the mechanism of the entanglement protection is analyzed in a special case with analytical solutions. In short, the entanglement loss caused by the dissipation to the bath might be weaken by introducing high‐frequency classical noises properly. The numerical simulations not only confirm the feasibility of protecting entanglement by noises but also reveal that the properties of the classical noises have a significant impact on the performance of the entanglement protection.