Topological Excitations in Ferroelectrics for Unconventional Computing

Modern electronics is currently facing a profound challenge. The demand for even smaller and more closely packed elements has hit a stumbling block: the power emitted in these devices releases more heat than can be efficiently removed; the scalability of the traditional devices cannot go below the atomic scale of 1nm; the clock rate of calculation is restricted by 100 GHz which is set by the restrictions of the frequency of the signal transmitted by a wire; big data processing volume and enormously growing data traffic amount and rate.<br/>We propose several solutions based on the unique functionality of electrically polarised nanomaterials, nanoferroelectrics, to host complex polarization textures that are incredibly stable due to topological self-protection mediated by elasticity and electrical boundary conditions.<br/><b>(i) Ferroelectric negative capacitance (NC) for low-dissipative nanoelectronics</b><br/>The operational functional element of the proposed circuit is a nanodot-scale capacitor with a ferroelectric spacer.<br/>We put forth a foundational mechanism of the NC demonstrating the inevitable emergence of the NC due to the formation of polarization domains. We establish a practical design of the stable and reversible NC FET based on the domain layout. The proposed device is tunable and downscales to the 2.5–5 nm technology node.<br/><b>(ii) Ferroelectric THz vibrations for ultrafast nanoelectronics</b><br/>The suggested technology employs a ferroelectric material with a ferroelectric-dielectric heterostructure as a resonator for electrons of an electrical circuit or for a terahertz electromagnetic wave. A peculiarity of the described structure is that the polarization of each ferroelectric layer variates periodically in space, forming a set of domains that exhibits a diverse wealth of oscillation modes in the terahertz spectral band. These vibration modes are directly coupled with the applied electromagnetic field. Because of its small size, the ferroelectric terahertz-generating device can be used as a resonator in wireless circuits, for instance, as a resonator in the terahertz antennas, a sensor of terahertz radiation, and a detector of the terahertz signals injected by an adjacent electrical device integrated into the same chip<br/><b>(iii) Ferroelectric tunable chirality for optoelectronics</b><br/>The topological chirality in nanostructured ferroelectrics is intimately related to topological polarization ordering. It emerges together with the polarization by spontaneous symmetry breaking from the non-chiral paraelectric state. This synergistic connection provides, possibly, <br/>the most important operational feature of the topological chirality in ferroelectrics: it can be tuned and manipulated by changing the polarization ordering. Given that the latter is directly coupled to an electric field, the chirality switching, hence optical activity manipulation, by the electric field offers a remarkable operational platform, which looks extremely attractive, especially because such an opportunity is unique in nature<br/><b>(iv) Ferroelectric multilevel logic unit for non von Neumann & neuromorphic computing</b><br/>We establish that ferroelectric nanodots hold two, three, or even four polarization states that are energetically stable thus providing a platform for encoding information. We reveal stable configurations and how to manipulate the polarization to move it between stable positions using electric fields. The important problems we address are the novel data protection and encryption protocols implementing these states and the ways the multilevel systems can enhance machine learning capable of better-emulating systems like the human brain, since., they do not only allow basic states like yes/no, but also yes/maybe/no or even more refined multi-logic levels.