Coulomb Blockade and Possible Luttinger Liquid Behaviors in Encapsulated High-Mobility Graphene Nanoribbons

Graphene nanoribbons (GNRs) are highly promising for exploring one-dimensional (1D) correlation physics and constructing digital logic circuits. Here, we report the intrinsic electrical transport behaviors of GNR field-effect transistors (FETs) fabricated using GNRs <i>in situ</i> encapsulated by hexagonal boron nitride (hBN) flakes. The FET devices exhibit excellent performance at room temperature: mobility up to ∼5000 cm² V^-1 s^-1, on/off ratio up to ∼10⁶, and subthreshold swing down to ∼70 mV dec^-1. The devices exhibit periodic conductance peaks and regular Coulomb diamonds due to strong electron-electron repulsion at cryogenic temperatures. Additionally, conductance of the GNR devices exhibits power-law dependence and universal scaling, signatures of Luttinger liquid behaviors, with a tunable Luttinger parameter <i>g</i> ranging from 0.1 to 0.3. Our study demonstrates that the <i>in situ</i> encapsulated GNRs can function as both high-performance FET devices and strongly interacting 1D quantum systems, providing an ideal platform for studying 1D transport and correlated physics.