Final Report Summary - E-CONTROL (Electric-Field Control of Magnetic Domain Wall Motion and Fast Magnetic Switching: Magnetoelectrics at Micro, Nano, and Atomic Length Scales)
Solid-state systems with competing order are a test bed for fundamental physical phenomena and enablers of new functionalities. Examples include ferromagnetic-antiferromagnetic, metal-insulating, and magnetic-superconducting hybrids. Multiferroic materials which are characterized by the coexistence of spontaneous magnetic and ferroelectric order constitute another thriving research field. Recent high-profile activities on multiferroics are driven by fundamental interests in ferroic order competition as well as the promise of electric-field tunable magnetism and magnetic-field controlled ferroelectricity. In E-CONTROL, we explored strain-coupled multiferroic heterostructures and studied their physical properties at different lengths scales. Key results include the demonstration of full domain pattern transfer from a ferroelectric layer to a ferromagnetic film, breakdown of this phenomenon at small length scales, reversible electric-field driven magnetic domain wall motion without an external magnetic field and/or a polarized electric current, electric-field induced magnetic switching in systems with in-plane and perpendicular magnetic anisotropy, emission of short-wavelength spin waves, spin-wave confinement, and the demonstration of magnetic logic operations. Besides, an in situ transmission electron microscopy technique for high-resolution analysis of electric-field effects was developed.