Fig. 1: Doubly aligned h-BN/graphene/h-BN.
From: Correlated states in doubly-aligned hBN/graphene/hBN heterostructures
a Schematics of a device with dual moiré, equipped with dual gates. Vtg and Vbg represent voltages of the top and bottom gate, respectively. b Art view of the lattice configuration with twist angles (θt and θb) between graphene and the top/bottom h-BN, as marked in the circled area in (a). c Optical micrograph image of the raw flakes stacked with their exfoliated straight edges (marked as coloured arrow) aligned. The white dashed line shows the contour of graphene. d Optical micrograph image of a typical completed device, consisting of a dual-gated doubly aligned h-BN/graphene/h-BN heterostructure. Scale bars in (c) and (d) are 10 μm and 5 μm, respectively. e Field effect curves tested in ambient condition of several typical devices, with different twist angles of θt and θb. Trace and re-trace curves recorded by sweeping up and down the gate voltages, as indicated by the arrows. f Raman spectra in the vicinity of graphene 2D peak of the corresponding devices in (e), and illustrated using the same colour code as in (e), with the dashed line arrows indicating the transition from misaligned to aligned regime. Scales are renormalized according to the peak height of the graphite gate and shifted for clarity.
