Second‐Order Synaptic Memory using Inherent Plasticity of Moiré Superlattices

Year: 2025

Type: article

Abstract: Achieving synaptic functionality electronically in a single-element quantum material is a fundamental challenge, as conventional methods rely on the introduction of extrinsic charge-traps or polar components. Here, it is demonstrated that twisted double bilayer graphene (tDBLG) moiré superlattices-composed purely of carbon-exhibit electronic hysteresis and plasticity in presence of twist-angle disorder. Inversion symmetry breaking at the moiré length scales also gives rise to second-order nonlinear electrical response via disorder-mediated extrinsic mechanisms. Such second-order nonlinearity is highly tunable in both sign and magnitude by varying carrier concentration and vertical displacement field. The coexistence of electronic plasticity and second-order nonlinearity is harnessed to realize a second-order synaptic memory device. These findings establish strained moiré carbon systems as a powerful new platform for energy-efficient neuromorphic computing, demonstrating that complex electronic functionality can emerge purely from symmetry-breaking physics in a single-element material.

Source: Advanced Materials

DOI: 10.1002/adma.202509837

Authors: Tanweer Ahmed, Kenji Watanabe, Takashi Taniguchi, Fèlix Casanova, Luis E. Hueso

Institutions: CIC nanoGUNE, National Institute for Materials Science, Ikerbasque

Language: English

Topic: Advanced Memory and Neural Computing

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: green

Funders: European Commission, Ministry of Education, Culture, Sports, Science and Technology, Ministerio de Ciencia e Innovación, Japan Society for the Promotion of Science, Japan Science and Technology Agency, European Regional Development Fund, Agencia Estatal de Investigación, Core Research for Evolutional Science and Technology

OpenAlex ID: W4413258483