Patents
A method employs a device with a heterostructure as a resonator for electrons of an electrical circuit or for a terahertz electromagnetic wave. The heterostructure comprises at least one dielectric layer and at least one ferroelectric layer. The at least one ferroelectric layer comprises a plurality of ferroelectric polarization domains. The plurality of ferroelectric polarization domains forms a polarization pattern. The polarization pattern is adapted to perform an oscillation with a resonance frequency in a terahertz frequency range. The method comprises functionally coupling the oscillation of the polarization pattern and an oscillation of the electrons of the electrical circuit or of the terahertz electromagnetic wave by the device.
Field effect transistor with a negative capacitance gate structure, US2022344471A1 · Filed Apr 15, 2022
A field effect transistor has a negative capacitance gate structure. The field effect transistor comprises a channel and a gate dielectric arranged over the channel. The negative capacitance gate structure comprises a bottom electrode structure comprising a bottom electrode, a multi-domain structure, and a top electrode structure. The multi-domain structure comprises a multi-domain element arranged over the bottom electrode, the multi-domain element comprising a plurality of topological domains and at least one topological domain wall. The top electrode structure comprises a top electrode arranged over the multi-domain element. At least a section of the bottom electrode structure of the negative capacitance gate structure is arranged over the gate dielectric and adapted to be coupled to the channel through the gate dielectric.
Thermal and electromagnetic generation and switching of chirality in ferroelectrics, EP4160707A1 · Filed Sep 29, 2021
A nanostructured ferroelectric is adapted to provide a high-temperature state and a low-temperature ferroelectric state. In the low-temperature ferroelectric state the nanostructured ferroelectric has a polarization state from a plurality of polarization states. The plurality of polarization states comprises at least a first chiral polarization state with a first chirality and a second chiral polarization state with a second chirality different from the first chirality. A method for generating a nanostructured ferroelectric with a predefined chirality comprises: Selecting the predefined chirality from the first chirality and the second chirality ; selecting an electromagnetic field according to the predefined chirality; providing the nanostructured ferroelectric in the high-temperature state; applying the electromagnetic field to the nanostructured ferroelectric in the high-temperature state; and cooling, while applying the electromagnetic field, the nanostructured ferroelectric from the high-temperature state to the low-temperature ferroelectric state to establish the polarization state of the nanostructured ferroelectric with the predefined chirality.