  The understanding of and control over light emission from quantum tunneling
has challenged researchers for more than four decades due to the intricate
interplay of electrical and optical properties in atomic scale volumes. Here we
introduce a device architecture that allows for the disentanglement of
electronic and photonic pathways - van der Waals quantum tunneling devices. The
electronic properties are defined by a stack of two-dimensional atomic crystals
whereas the optical properties are controlled via an external photonic
architecture. In van der Waals heterostructure made of gold, hexagonal boron
nitride and graphene we find that inelastic tunneling results in the emission
of photons and surface plasmon polaritons. By coupling these heterostructures
to optical nanocube antennas we achieve resonant enhancement of the photon
emission rate in narrow frequency bands by four orders of magnitude. Our
results lead the way towards a new generation of nanophotonic devices that are
driven by quantum tunneling.
