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arXiv · 1802.03758

Photoexcitation Cascade and Quantum-Relativistic Jets in Graphene

Cyprian Lewandowski·L. S. Levitov
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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 ${\sim}10$ secondary carriers per single absorbed photon.

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Cyprian Lewandowski, L. S. Levitov. 2018-02-11. Photoexcitation Cascade and Quantum-Relativistic Jets in Graphene. https://doi.org/10.1103/physrevlett.120.076601

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