High critical current density and enhanced irreversibility field in superconducting MgB2 thin films. di Eom, C, Lee, M, Choi, J, Belenky, L, Song, X, Cooley, L, Naus, M, Patnaik, S, Jiang, J, Rikel, M, Polyanskii, A, Gurevich, A, Cai, X, Bu, S, Babcock, SE, Hellstrom, E, Larbalestier, D, Rogado, N, Regan, K, Hayward, M, He, T, Slusky, J, Inumaru, K, Haas, M, Cava, R