Sustained charge-echo entanglement in a two charge qubits under random telegraph noise

The echo signal influence in restoring the coherence lost due to a random telegraph noise (RTN) in a double quantum dot has been theoretically investigated. In this paper, we discuss the RTN effects according to two different protocols manipulations: free induction and echo signal. The time evolution of the coherence factor for both protocols is evaluated employing the equation of motion approach. The time dependence of both fidelity and purity is numerically assessed as well. Our results unveil an enhancement in the entangled states lifetime and how the effects of the RTN, ubiquitous to the solid-state devises, can be counteracted. Furthermore, applying charge-echo stretches the coherence time. Our results exhibit an improvement by 4 times of the coherence time, proving the echo signal efficiency. It is worth mentioning that our analysis is also applicable to other solid-state devices and helpful for further understanding the open quantum systems dynamics.