Concurrence and entanglement on a 16-site spin-1/2 pyrochlore cluster

Abstract

We examine the entanglement of the ground state of a 16-site spin-1/2 pyrochlore cluster in the quantum spin ice regime via various calculations of $\mathcal{I}$-concurrence. Exact ground state solutions to a quantum spin Hamiltonian with four nearest-neighbour exchange parameters were obtained using exact diagonalization. We present results for the ground state $\mathcal{I}$-concurrence in a region within the parameter space of the model where the ground state is a singlet. We discuss variations in the $\mathcal{I}$-concurrence in the context of the composition of the ground state and we demonstrate how a lattice distortion disentangles the state.