We describe a tunneling spectroscopy technique in a double bilayer graphene heterostructure where momentum-conserving tunneling between different energy bands serves as an energy filter for the tunneling carriers, and allows a measurement of the quasi-particle state broadening at well defined energies. The broadening increases linearly with the excited state energy with respect to the Fermi level, and is weakly dependent on temperature. In-plane magnetotunneling reveals a high degree of rotational alignment between the graphene bilayers, and an absence of momentum randomizing processes.
@article{arxiv.2105.07104,
title = {Quantum Lifetime Spectroscopy and Magnetotunneling in Double Bilayer Graphene Heterostructures},
author = {Nitin Prasad and G. William Burg and Kenji Watanabe and Takashi Taniguchi and Leonard F. Register and Emanuel Tutuc},
journal= {arXiv preprint arXiv:2105.07104},
year = {2021}
}