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تسجيل مستخدم جديدSoft pair excitations and double-log divergences due to carrier interactions in graphene
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Interactions between charge carriers in graphene lead to logarithmic renormalization of observables mimicking the behavior known in (3+1)-dimensional quantum electrodynamics (QED). Here we analyze soft electron-hole (e-h) excitations generated as a result of fast charge dynamics, a direct analog of the signature QED effect - multiple soft photons produced by the QED vacuum shakeup. We show that such excitations are generated in photon absorption, when a photogenerated high-energy e-h pair cascades down in energy and gives rise to multiple soft e-h excitations. This fundamental process is manifested in a double-log divergence in the emission rate of soft pairs and a characteristic power-law divergence in their energy spectrum of the form $frac{1}{omega}ln left(frac{omega}{Delta}right) $. Strong carrier-carrier interactions make pair production a prominent pathway in the photoexcitation cascade.
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