Electronic Subband Reconfiguration in a d 0 -Perovskite Induced by Strain-Driven Structural Transformations
Résumé
It is well known that transport in lightly n-doped SrTiO 3 involves light and heavy electron bands. We have found that upon application of moderate quasi-isotropic pressures, the relative positions of these subbands are changed by a few meV and, eventually, a band inversion occurs at $1 kbar. Such effects are, however, suppressed in the closely related KTaO 3 perovskite. We show that the extremely subtle electronic reconfiguration in SrTiO 3 is triggered by strain-induced structural transformations that are accompanied by remarkable mobility enhancements up to about Á= % 300%. Our results provide a microscopic rationale for the recently discovered transport enhancement under strain and underscore the role of the internal structural degrees of freedom in the modulation of the perovskite electronic properties.