1210.0799 (Fei Lin et al.)

Enhancing the thermal stability of entanglement between Majorana
fermions with dipoles in optical lattices    [PDF]

Fei Lin, V. W. Scarola

Pairing between spinless fermions can generate Majorana fermion excitations. Such excitations may exhibit intriguing properties arising from non-local entanglement, including anyonic braid statistics, teleportation, and enough stability to encode quantum information. But simple models indicate that non-local entanglement between Majorana fermions becomes unstable at non-zero temperatures. We address this issue here by showing that anisotropic interactions between dipolar fermions in optical lattices can be used to form domains that significantly enhance thermal stability. We construct a model of oriented dipolar fermions in a square optical lattice. We explicitly compute the correlation functions defining entanglement. We find that domains established by strong interactions exhibit enhanced entanglement between Majorana fermions over large distances and long times even at finite temperatures. Our approach can be generalized to a variety of configurations and other systems, such as quantum wire arrays.

View original: http://arxiv.org/abs/1210.0799