We explore the energetics of microwaves interacting with a double quantum dot photodiode and show wave-particle aspects in photon-assisted tunneling. The experiments show that the single photon energy sets the relevant absorption energy in a weak-drive limit, which contrasts the strong drive limit where the wave amplitude determines the relevant-energy scale and opens up microwave induced bias triangles. The threshold condition between these two regimes is set by the fine-structure constant of the system. The energetics are determined here with the detuning conditions of the double dot system and stopping-potential measurements that constitute a microwave version of the photoelectric effect.
@article{arxiv.2208.01323,
title = {Energetics of microwaves probed by double quantum dot absorption},
author = {Subhomoy Haldar and Harald Havir and Waqar Khan and Sebastian Lehmann and Claes Thelander and Kimberly A. Dick and Ville F. Maisi},
journal= {arXiv preprint arXiv:2208.01323},
year = {2023}
}