Non-collinear and asymmetric polar moments at back-gated SrTiO3 interfaces

• DOI: 10.1038/s42005-022-00905-3
• Publication Date: 2022-05-30T10:04:00Z
• Authors: Fryderyk Lyzwa; Yurii G. Pashkevich; Premysl Marsik; Andrei Sirenko; Andrew Chan; Benjamin P. P. Ma...; Meghdad Yazdi-Rizi; Bing Xu; Luis M. Vicente-A...; Diogo C. Vaz; Gervasi Herranz; Maximilien Cazayous; Pierre Hemme; Katrin Fürsich; Matteo Minola; Bernhard Keimer; Manuel Bibes; Christian Bernhard
• Keywords: QB460-466; Ferroelectricity; Physics; QC1-999; 0103 physical sciences; Phase-transition; Astrophysics; Field control modes; 01 natural sciences; Electric-field control

Abstract The mechanism of the gate-field-induced metal-to-insulator transition electrons at interface SrTiO 3 with LaAlO or AlO x is great current interest. Here, we show infrared ellipsometry and confocal Raman spectroscopy that an important role played by a polar lattice distortion non-collinear, highly asymmetric hysteretic respect to gate field. anomalous behavior large lateral component underlying local electric field explained in terms interplay between oxygen vacancies, tend migrate form extended clusters antiferrodistortive domain boundaries, interfacial electrons, which get trapped/detrapped vacancy under positive/negative bias. Our findings open new perspectives for defect engineering devices strongly enhanced fields can be manipulated various parameters, like strain, temperature, photons.