We consider two qubits undergoing local dissipation and subject to local driving. We then determine the optimal Markovian feedback action to preserve initial entanglement as well as to create stationary entanglement with the help of an $\text{XY}$ interaction Hamiltonian. Such feedback actions are worked out in a way not depending on the initial two-qubit state, whence called universal.

• Received 7 April 2017

DOI:https://doi.org/10.1103/PhysRevA.96.012340