Tuning the Charge Distribution via Strain Engineering in Manganite-Cuprate Heterostructures*

The exploration of strain engineering in complex oxide heterostructures has unveiled the microscopic origins of macroscopic properties and led to the precise control of the local physical behavior in materials at the nanoscale. Here, we reveal the local charge distribution in manganese oxides by means of high spatial and energy resolution scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS). Our direct quantification of charge arrangement gives insight into how the strain locally alters the physical properties of La_0.5Sr_0.5MnO₃ - La₂CuO₄ heterostructures. We find that the magnitude of the charge redistribution can be controlled via the epitaxial strain, which further influences the macroscopic electronic and magnetic structures differently from the strain affects reported on single-phase films. Our findings offer a new way of controlling local phases in manganites and novel design of relevant electronic and spintronic devices.