Orbital control in strained ultra-thin LaNiO3/LaAlO3 superlattices J. W. Freeland, Jian Liu, M. Kareev, B. Gray, J. W. Kim, P. Ryan, R. Pentcheva and J. Chakhalian EPL, 96 5 (2011) 57004 Published online: 22 November 2011 DOI: 10.1209/0295-5075/96/57004