Effects of electric fields on ultracold Rydberg atom interactions - Cabral, Jader de Souza; Kondo, Jorge Douglas Massayuki; Gonçalves, L. F.; Nascimento, V. A.; Marcassa, Luís Gustavo; Booth, D.; Tallant, J.; Schwettmann, A.; Overstreet, K. R.; Sedlacek, J.; Shaffer, J. P. (Journal of Physics B, 2011)