Small polaron-mediated zero differential transconductance of 2D semiconductor/CoFe₂O₄ heterojunctions for plateau transistor applications.

Abstract

The binary paradigm of modern electronics imposes intrinsic limits on information density and energy efficiency. Zero differential transconductance (ZDT)-based multi-valued logic (MVL) offers a promising alternative, providing a compelling platform for MVL architectures. However, achieving stable and tunable ZDT operation remains challenging due to the difficulty of precisely controlling ZDT behavior. Here, we present the plateau transistors (ptTs), which enables highly tunable, intrinsic ternary operation through a distinctive polaron-mediated charge transport mechanism. Polaronic behavior in cobalt ferrite (CoFe₂O₄) was predicted through simulations and subsequently confirmed using a designed charge-smearing near-infrared spectroscopy technique. Incorporating a CoFe₂O₄ gate dielectric yields stable near-ZDT operation within a standard field-effect transistor architecture, enabling distinct electrical separation of multiple logic states. We further demonstrated that this approach is broadly applicable to a wide range of 2D materials, including MoS₂, graphene, and WSe₂. The demonstrated ternary operation provides a viable device-level platform for multi-level signal representation, offering new opportunities for energy-efficient electronic devices.