Gate-Tunable Resonant Tunneling in a Dual-Gated Twist-Controlled Double Monolayer Graphene-hBN Heterostructure

Van der Waals heterostructures of two-dimensional (2D) crystals are a versatile platform for electron physics and device applications. An emerging device that departs markedly from the field-effect transistor, and has shown potential applications for logic [1], memory [2], and security [3] is the interlayer resonant tunneling field-effect transistor (ITFET), consisting of two independently contacted 2D layers separated by a tunnel barrier. In such devices, energy and momentum conservation during tunneling leads to interlayer voltage-current characteristics with gate-tunable negative differential resistance (NDR). ITFET demonstrations include single-gated double monolayer or double bilayer graphene separated by hexagonal boron-nitride (hBN) [4]–[5], dual-gated double bilayer graphene separated by WSe2 [6], and dual-gated double WSe2 separated by hBN barriers [7]. Here, we present a combined experimental and modeling study of dual-gated double monolayer graphene-hBN heterostructures, where the crystals axes of the two graphene electrodes are rotationally aligned, thereby enabling resonant tunneling and gate-tunable NDR.