Current amplification and relaxation in Dirac systems

Abstract

We study how electron-electron (e-e) interactions affect the current carried by excited electrons and holes in Dirac systems such as graphene or topological insulators. We find that the current shows distinctly different behavior for e-e collisions involving the electron or the hole. Most surprisingly, for positive Fermi energy, collisions of the electrons can substantially increase the current. This remarkable amplification of the current can be of the order of $\sim 10\%$ per scattering event. It also causes a strong suppression of the overall current relaxation rate of a photoexcited electron-hole pair, with the amplification of the electron current making up for a fast decay of the hole current.

4 pages, 4 figures + references + supplemental material

References in corpus (15)

• The electronic properties of graphene
• Two Dimensional Atomic Crystals
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Topological Insulators with Inversion Symmetry
• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• Spintronics and Pseudospintronics in Graphene and Topological Insulators
• Electronic transport in graphene: A semi-classical approach including midgap states
• Ultrafast Optical Excitation of a Persistent Surface-State Population in the Topological Insulator Bi2Se3
• Friedel oscillations, impurity scattering and temperature dependence of resistivity in graphene
• Ultrafast surface carrier dynamics in the topological insulator Bi2Te3
• Spatially resolved femtosecond pump-probe study of topological insulator Bi2Se3
• Collective cyclotron motion of the relativistic plasma in graphene
• Photo-excited Carrier Dynamics and Impact Excitation Cascade in Graphene
• Anisotropy of excitation and relaxation of photogenerated Dirac electrons in graphene
• Energy relaxation and thermalization of hot electrons in quantum wires

Cited by in corpus (6)

• Microscopic Origins of Hydrodynamic Transport in Type-II Weyl Semimetal WP${}_2$
• Infrared/Terahertz Spectra of the Photogalvanic Effect in (Bi,Sb)Te based Three Dimensional Topological Insulators
• Terahertz Photogalvanic Spectroscopy of Three Dimensional Topological Insulators
• Coherent ultrafast spin-dynamics probed in three dimensional topological insulators
• Current enhancement due to field-induced dark carrier multiplication in graphene
• Giant intrinsic photoresponse in pristine graphene