Local permutations of products of Bell states and entanglement distillation

Abstract

We present different algorithms for mixed-state multicopy entanglement distillation for pairs of qubits. Our algorithms perform significantly better than the best-known algorithms. Better algorithms can be derived that are tuned for specific initial states. These algorithms are based on a characterization of the group of all locally realizable permutations of the $4^n$ possible tensor products of n Bell states.