Multiband Mechanism for the Sign Reversal of Coulomb Drag Observed in Double Bilayer Graphene Heterostructures

Abstract

Coupled 2D sheets of electrons and holes are predicted to support novel quantum phases. Two experiments of Coulomb drag in electron-hole (e-h) double bilayer graphene (DBLG) have reported an unexplained and puzzling sign reversal of the drag signal. However, we show that this effect is due to the multiband character of DBLG. Our multiband Fermi liquid theory produces excellent agreement and captures the key features of the experimental drag resistance for all temperatures. This demonstrates the importance of multiband effects in DBLG: they have a strong effect not only on superfluidity, but also on the drag.

5 pages, 3 figures

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Cited by in corpus (4)

• Hidden Wave Function of Twisted Bilayer Graphene: Flat Band as a Landau Level
• First-principles quantum corrections for carrier correlations in double-layer two-dimensional heterostructures
• Correlation functions in electron-electron and electron-hole double quantum wells: Temperature, density and barrier-width dependence
• Coulomb drag in metallic twisted bilayer graphene