Entanglement echoes in quantum computation
Davide Rossini, Giuliano Benenti, Giulio Casati · Physical Review A · 2004
We study the stability of entanglement in a quantum computer implementing an efficient quantum algorithm, which simulates a quantum chaotic dynamics. For this purpose, we perform a forward-backward evolution of an initial state in which two qubits are in a maximally entangled Bell state. If the dynamics is reversed after an evolution time ${t}_{r}$, there is an echo of the entanglement between these two qubits at time ${t}_{e}=2{t}_{r}$. Perturbations attenuate the pairwise entanglement echo and generate entanglement between these two qubits and the other qubits of the quantum computer.