title: Polar antiferromagnets produced with orbital order.
abstract: Polar states are realized in pseudocubic manganite films fabricated on high-index substrates, in which a Jahn-Teller (JT) distortion remains an active variable. Several types of orbital orders (OOs) were found to develop large optical second harmonics, signaling broken-inversion symmetry distinct from their bulk forms and films on (100) substrates. The observed symmetry lifting and first-principles calculation both indicate that the modified JT q2 mode drives Mn-site off centering, which can be controlled by a magnetic-field-induced phase transition via a coupling of OO and spin orders.
authors.affiliation: Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan. ogawa@myn.rcast.u-tokyo.ac.jp
authors.forename: Naoki
authors.initials: N
authors.lastname: Ogawa
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ogimoto
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ida
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Nomura
authors.forename: Ryotaro
authors.initials: R
authors.lastname: Arita
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Miyano