Manipulating chiral spin transport with ferroelectric polarization.

A magnon is a collective excitation of the spin structure in a magnetic insulator and can transmit spin angular momentum with negligible dissipation. This quantum of a spin wave has always been manipulated through magnetic dipoles (that is, by breaking time-reversal symmetry). Here we report the experimental observation of chiral spin transport in multiferroic BiFeO and its control by reversing the ferroelectric polarization (that is, by breaking spatial inversion symmetry).

Light-driven dynamical tuning of the thermal conductivity in ferroelectrics.

Dynamical tuning of the thermal conductivity in crystals, , is critical for thermal management applications, as well as for energy harvesting and the development of novel devices able to perform logic operations with phonons. Such a desired control can be achieved in functional materials that experience large structural and phonon variations as a result of field-induced phase transformations. However, this approach is only practical within reduced temperature intervals containing zero-bias phase transition points, since otherwise the necessary driving fields become excessively large and the materials' performances are detrimentally affected.

A 2D ferroelectric vortex pattern in twisted BaTiO freestanding layers.

The wealth of complex polar topologies recently found in nanoscale ferroelectrics results from a delicate balance between the intrinsic tendency of the materials to develop a homogeneous polarization and the electric and mechanical boundary conditions imposed on them. Ferroelectric-dielectric interfaces are model systems in which polarization curling originates from open circuit-like electric boundary conditions, to avoid the build-up of polarization charges through the formation of flux-closure domains that evolve into vortex-like structures at the nanoscale level. Although ferroelectricity is known to couple strongly with strain (both homogeneous and inhomogeneous), the effect of mechanical constraints on thin-film nanoscale ferroelectrics has been comparatively less explored because of the relative paucity of strain patterns that can be implemented experimentally.

Electrically induced cancellation and inversion of piezoelectricity in ferroelectric HfZrO.

HfO-based thin films hold huge promise for integrated devices as they show full compatibility with semiconductor technologies and robust ferroelectric properties at nanometer scale. While their polarization switching behavior has been widely investigated, their electromechanical response received much less attention so far. Here, we demonstrate that piezoelectricity in HfZrO ferroelectric capacitors is not an invariable property but, in fact, can be intrinsically changed by electrical field cycling.

Prenatal aneuploidy screening in a low-risk Hispanic population: price elasticity and cost-effectiveness.

Background: In October 2015, the Massachusetts Medicaid program temporarily stopped reimbursement for procedures in which the International Classification of Diseases, Tenth Edition, code for serum aneuploidy screening used by certain communities was stipulated. This change led to a substantial number of patients who went without aneuploidy screening for approximately 3 years.

Objective: This study aimed to determine the change in use and cost-effectiveness of prenatal aneuploidy serum screening in a low-risk Hispanic Medicaid population in Massachusetts.