Coherent Interlayer Tunneling and Negative Differential Resistance with High Current Density in Double Bilayer Graphene-WSe2 Heterostructures

We demonstrate gate-tunable resonant tunneling and negative differential resistance between two rotationally aligned bilayer graphene sheets separated by bilayer WSe2. We observe large interlayer current densities of 2 and 2.5 mu A/mu m(2) and peak-to-valley ratios approaching 4 and 6 at room temperature:and 1.5 K, respectively,; values that are comparable to epitaxially grown resonant tunneling heterostructures. An; excellent agreement between theoretical calculations Whig a Lorentzian spectral function for the two-dimensional quasiparticle states, and the experimental data indicates that the interlayer current stems primarily from energy and in-plane momentum conserving 2D-2D tunneling, with minimal contributions from inelastic or non-momentum-conserving tunneling. We demonstrate narrow tunneling resonances with intrinsic-half-widths of 4 and 6 meV at 1.5 and 300 K, respectively.