Bulk-suppressed and surface-sensitive Raman scattering by transferable plasmonic membranes with irregular slot-shaped nanopores.

Raman spectroscopy enables the non-destructive characterization of chemical composition, crystallinity, defects, or strain in countless materials. However, the Raman response of surfaces or thin films is often weak and obscured by dominant bulk signals. Here we overcome this limitation by placing a transferable porous gold membrane, (PAuM) on the surface of interest.

Reversible Optical Control of Polarization in Epitaxial Ferroelectric Thin Films.

Light is an effective tool to probe the polarization and domain distribution in ferroelectric materials passively, that is, non-invasively, for example, via optical second harmonic generation (SHG). With the emergence of oxide electronics, there is now a strong demand to expand the role of light toward active control of the polarization. In this work, optical control of the ferroelectric polarization is demonstrated in prototypical epitaxial PbZrTiO (PZT)-based heterostructures.

Defeating depolarizing fields with artificial flux closure in ultrathin ferroelectrics.

Material surfaces encompass structural and chemical discontinuities that often lead to the loss of the property of interest in so-called dead layers. It is particularly problematic in nanoscale oxide electronics, where the integration of strongly correlated materials into devices is obstructed by the thickness threshold required for the emergence of their functionality. Here we report the stabilization of ultrathin out-of-plane ferroelectricity in oxide heterostructures through the design of an artificial flux-closure architecture.

Imaging ferroelectric domains with a single-spin scanning quantum sensor.

The ability to sensitively image electric fields is important for understanding many nanoelectronic phenomena, including charge accumulation at surfaces and interfaces and field distributions in active electronic devices. A particularly exciting application is the visualization of domain patterns in ferroelectric and nanoferroic materials, owing to their potential in computing and data storage. Here, we use a scanning nitrogen-vacancy (NV) microscope, well known for its use in magnetometry, to image domain patterns in piezoelectric (Pb[ZrTi]O) and improper ferroelectric (YMnO) materials through their electric fields.