Lifeboat Foundation

Circa 2005

We search for translationally invariant states of qubits on a ring that maximize the nearest neighbor entanglement. This problem was initially studied by O’Connor and Wootters [Phys. Rev. A {\bf 63}, 052302 (2001)]. We first map the problem to the search for the ground state of a spin 1/2 Heisenberg XXZ

Model. Using the exact Bethe ansatz solution in the limit of an infinite ring.

We prove the correctness of the assumption of O’Connor and Wootters that the state of maximal entanglement does not have any pair of neighboring spins.

“down’’ (or, alternatively spins “up’‘).