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 uA/um2 and 2.5 uA/um2, 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 using a Lorentzian spectral function for the two-dimensional (2D) 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 K and 300 K, respectively.
@article{arxiv.1706.08034,
title = {Coherent Interlayer Tunneling and Negative Differential Resistance with High Current Density in Double Bilayer Graphene-WSe2 Heterostructures},
author = {G. William Burg and Nitin Prasad and Babak Fallahazad and Amithraj Valsaraj and Kyounghwan Kim and Takashi Taniguchi and Kenji Watanabe and Qingxiao Wang and Moon J. Kim and Leonard F. Register and Emanuel Tutuc},
journal= {arXiv preprint arXiv:1706.08034},
year = {2017}
}