Photoexcitation Cascade and Quantum-Relativistic Jets in Graphene
Abstract
In Dirac materials linear band dispersion blocks momentum-conserving interband transitions, creating a bottleneck for electron-hole pair production and carrier multiplication in the photoexcitation cascade. Here we show that the decays are unblocked and the bottleneck is relieved by subtle many-body effects involving multiple off-shell e-h pairs. The decays result from a collective behavior due to emission of many soft pairs. We discuss characteristic signatures of the off-shell pathways, in particular the sharp angular distribution of secondary carriers, resembling relativistic jets in high-energy physics. The jets can be directly probed using solid-state equivalent of particle detectors. Collinear scattering enhances carrier multiplication, allowing for emission of as many as secondary carriers per single absorbed photon.
Keywords
Cite
@article{arxiv.1802.03758,
title = {Photoexcitation Cascade and Quantum-Relativistic Jets in Graphene},
author = {Cyprian Lewandowski and L. S. Levitov},
journal= {arXiv preprint arXiv:1802.03758},
year = {2018}
}
Comments
11 pages, 3 figures