常誘電非磁性体CaTiO₃中のホールPolaronによる単一原子スケールマルチフェロイクスの創出

抄録

We investigate the emergence of single atomic scale multiferroics by a hole polaron in paraelectric and nonmagnetic CaTiO₃ using first-principles calculations. A hole localizes on one oxygen in CaTiO₃ with local lattice distortions, namely forming a hole polaron. Polarization is emerged at the local area of about 8 Å × 4 Å × 4 Å around a hole polaron because of lattice distortions induced by a hole polaron. In addition, magnetization is emerged on one oxygen where a hole polaron is formed because of spin polarization of a hole. The emergence areas of both properties are smaller than critical size where they vanish. Therefore, the local area where a hole polaron is formed exhibits polarization and magnetization and can be considered as a single atomic scale multiferroics.