Role of locally polar regions in the superconductivity of SrTi O 3

A possible cooperation between ferroelectric and superconducting order parameters in SrTiO${}_{3}$ has long been suspected. Here, the authors find that the superconducting critical temperature of SrTiO${}_{3}$ correlates with the length scale of polar order. The findings point to spin-orbit coupling as an important ingredient in the superconductivity of SrTiO${}_{3}$. The ability to control the size of the polar domains in thin films opens up new opportunities to control the superconductivity in SrTiO${}_{3}$ and other superconductors that exhibit local polar order