Electronic subband reconfiguration in a d0-perovskite induced by strain-driven structural transformations

Area of Science:

• Solid State Physics
• Materials Science
• Condensed Matter Physics

Background:

• Transport in lightly n-doped strontium titanate (SrTiO3) is characterized by the interplay of light and heavy electron bands.
• Understanding the electronic properties of perovskite materials is crucial for developing advanced electronic devices.

Purpose of the Study:

• To investigate the effects of quasi-isotropic pressure on the electronic band structure of SrTiO3.
• To elucidate the mechanism behind strain-induced mobility enhancements in SrTiO3.
• To compare the pressure-induced electronic reconfiguration in SrTiO3 with that in potassium tantalate (KTaO3).

Main Methods:

• Application of moderate quasi-isotropic pressures to SrTiO3 samples.
• Analysis of subtle changes in subband positions and band inversion using experimental techniques (details not specified in abstract).
• Comparative study with KTaO3 to highlight material-specific responses.

Main Results:

• A few meV shift in subband positions and band inversion occurring at approximately 1 kbar in SrTiO3.
• Suppression of these pressure-induced effects in KTaO3, indicating material specificity.
• Strain-induced structural transformations in SrTiO3 leading to remarkable electron mobility enhancements of up to ~300%.

Conclusions:

• The electronic reconfiguration in SrTiO3 under pressure is driven by strain-induced structural changes.
• These findings provide a microscopic explanation for the observed transport enhancement under strain in perovskites.
• The study highlights the significant role of internal structural degrees of freedom in modulating the electronic properties of perovskites.