Optical conductivity study of screening of many-body effects in graphene interfaces

Many-body effects on graphene conductivity: Quantum Monte Carlo calculations

Many-body renormalization of the minimal conductivity in graphene.

The conductance of ballistic graphene at the neutrality point is due to coherent electron tunneling between the leads, the so called pseudodiffusive regime. The conductance scales as a function of the sample dimensions in the same way as in a diffusive metal, despite the difference in the physical mechanisms involved. The electron-electron interaction modifies this regime, and plays a role simi...

Many-body exchange-correlation effects in graphene

We calculate, within the leading-order dynamical-screening approximation, the electron self-energy and spectral function at zero temperature for extrinsic (or gated/doped) graphene. We also calculate hot carrier inelastic scattering due to electron–electron interactions in graphene. We obtain the inelastic quasiparticle lifetimes and associated mean free paths from the calculated self-energy. T...

Many body effects at surfaces and interfaces

The past two decades have experienced the development of angle-resolved photoemission to the point that it can now provide crucial information on an energy scale that is relevant to many key problems in condensed matter physics. At the same time, our ability to prepare and characterize surfaces, interfaces, and thin films has improved to the extent that many exotic phases can be produced with a...

Excitonic effects in the optical conductivity of gated graphene.

We study the effect of electron-electron interactions in the optical conductivity of graphene under an applied gate and derive a generalization of Elliott's formula, commonly used for semiconductors, for the optical intensity. We show that excitonic resonances are responsible for several features of the experimentally measured midinfrared response of graphene such as the increase of the conduct...