Fig. 4: Effect of ferroelectric polarization on the interfacial potential well.
From: Enhanced superconductivity and coexisting ferroelectricity at oxide interfaces
a Schematic evolution of the dielectric constant (ε) of KTO under an applied external electric field, reproduced based on experimental results from refs. 39,41. The pink shading highlights the “0±” states, which exhibit a reduced ε compared to the “origin” state. b Potential well modulation (thick lines) and electron envelope wavefunction (thin lines) for original (dashed), “0−” (blue), and “0+” (red) states. Insets show competing fields from EP (ferroelectric polarization) and ES (screening charges). The net field Ebuilt-in = EP + ES modulates the well profiles. Post VG removal, persistent tuning (aligned with VG direction) suggests that | ES | > | EP |.
