Coulomb drag mechanisms in graphene.

Negative Coulomb Drag in Double Bilayer Graphene.

We report on an experimental measurement of Coulomb drag in a double quantum well structure consisting of bilayer-bilayer graphene, separated by few layer hexagonal boron nitride. At low temperatures and intermediate densities, a novel negative drag response with an inverse sign is observed, distinct from the momentum and energy drag mechanisms previously reported in double monolayer graphene. ...

Energy-driven drag at charge neutrality in graphene.

Coulomb coupling in graphene heterostructures results in vertical energy transfer between electrons in proximal layers. We show that, in the presence of correlated density inhomogeneity in the layers, vertical energy transfer has a strong impact on lateral charge transport. In particular, for Coulomb drag, its contribution dominates over conventional momentum drag near zero doping. The dependen...

Theory of Coulomb drag in graphene

We study the Coulomb drag between two single graphene sheets in intrinsic and extrinsic graphene systems with no interlayer tunneling. The general expression for the nonlinear susceptibility appropriate for single-layer graphene systems is derived using the diagrammatic perturbation theory, and the corresponding exact zerotemperature expression is obtained analytically. We find that, despite th...

Plasmon-mediated Coulomb drag between graphene waveguides

Coulomb drag in graphene near the Dirac point.

We study Coulomb drag in graphene near the Dirac point, focusing on the regime of interaction-dominated transport. We establish a novel, graphene-specific mechanism of Coulomb drag based on fast interlayer thermalization, inaccessible by standard perturbative approaches. Using the quantum kinetic equation framework, we derive a hydrodynamic description of transport in double-layer graphene in t...