Resonant Tunneling Oscillators Based on WSe<sub>2</sub>/<i>h</i>-BN/WSe<sub>2</sub> van der Waals Double Quantum Wells.

Kinoshita, Kei; Moriya, Rai; Ito, Mika; Nishimura, Arisa; Okazaki, Shota; Onodera, Momoko; Watanabe, Kenji; Taniguchi, Takashi et al. · Nano Lett · 2026

basic_science · Level V

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Abstract

A van der Waals (vdW) heterostructure of few-layer (FL)-WSe<sub>2</sub>/FL-<i>h</i>-BN/FL-WSe<sub>2</sub> exhibits resonant tunneling between the WSe<sub>2</sub> subbands through the <i>h</i>-BN barrier, analogous to that in conventional double-quantum-well (DQW) structures. This resonant tunneling in the vdW DQW device gives rise to pronounced negative differential resistance (NDR). Utilizing this NDR, we demonstrate a resonant tunneling oscillator: when the vdW DQW device is integrated into an LC resonant circuit and biased within its NDR region, sustained AC voltage oscillations are achieved with frequencies exceeding 1 MHz. Furthermore, a comparison of the oscillation characteristics of two different devices indicates that lowering the device resistance is a viable route toward higher-frequency operation. This work represents the first realization of oscillators based on resonant tunneling between transition-metal dichalcogenide layers, significantly broadening the potential of vdW electronics.