Spin correlation in kagomé ice state : neutron scattering study of the dipolar spin ice Dy 2 Ti 2 O 7 under magnetic field along [ 111 ]

Spin correlation in kagomé ice state: neutron scattering study of the dipolar spin ice Dy 2 Ti 2 O 7 under magnetic field along [111] Abstract We have investigated the kagomé ice state in the frustrated pyrochlore oxide Dy 2 Ti 2 O 7 under magnetic field along a [111] axis. Spin correlations have been measured by neutron scattering and analyzed by Monte-Carlo simulation. The kagomé ice state, which has a non-vanishing residual entropy well established for the nearest-neighbor spin ice model by the exact solution, has been proved to be realized in the dipolar-interacting spin ice Dy 2 Ti 2 O 7 by observing the characteristic spin correlations. The simulation shows that the long-range interaction gives rise to only weak lifting of the ground state degeneracy and that the system freezes within the degenerate kagomé ice manifold. The spin ice model, an Ising ferromagnet with a local <111> easy axis on the pyrochlore lattice interacting with nearest-neighbor exchange coupling, has attracted much attention because of its intriguing frustration mechanism [1].