Ab initio calculations of low-energy quasiparticle lifetimes in bilayer graphene

Motivated by recent experimental results [1], we calculate from first-principles the lifetime of low-energy (within 200 meV from the Fermi energy) quasiparticles in bilayer graphene. We take into account the scattering rate arising from electron-electron interactions within the GW-approximation for the electron self-energy and consider several p-type doping levels ranging from 0 to about 3x10^12 holes/cm^2. In the undoped case we find that the average inverse lifetime scales linearly with quasiparticle energy away from the charge neutrality point, with values in good agreement with experiments. In the doped case, the dependence of the inverse lifetime on quasiparticle energy acquires a non-linear component due to the opening of an additional decay channel mediated by acoustic plasmons.

[1] Nitin Prasad, G. William Burg, Kenji Watanabe , Takashi Taniguchi, Leonard F. Register, and Emanuel Tutuc, "Quantum Lifetime Spectroscopy and Magnetotunneling in Double Bilayer Graphene Heterostructures.", Phys. Rev. Lett. 127, 117701 (2021).