Erratum: In situ optical characterization of LaAlO3 epitaxy on SrTiO3(001) X. D. Zhu, Sebastian Wicklein, Felix Gunkel, Rui Xiao and Regina Dittmann EPL, 109 5 (2015) 59902 Published online: 23 March 2015 DOI: 10.1209/0295-5075/109/59902