Common anion rule in oxide heterointerfaces: Experimental verification by in situ photoemission spectroscopy oleh Ryotaro Hayasaka, Tatsuhiko Kanda, Yuuki Masutake, Duy Khanh Nguyen, Naoto Hasegawa, Seitaro Inoue, Asato Wada, Miho Kitamura, Daisuke Shiga, Kohei Yoshimatsu, Hiroshi Kumigashira