Orbital dependent Coulomb drag in electron-hole bilayer graphene heterostructures

We report Coulomb drag studies in an electron-hole bilayer graphene heterostructure in a magnetic field, where the orbital, spin, and valley degrees of freedom are lifted by the combined effects of exchange interaction, Zeeman energy, and vertical displacement field. Our device enables the application of a large vertical displacement field in both layers. In addition to the well-established strong Coulomb drag between the Landau levels with an orbital quantum number N = 0, we observe a Coulomb drag signal between the N = 1 Landau levels under a suitable vertical displacement field. As the displacement field increases further, the Coulomb drag signal between N = 1 Landau levels weakens, and a Coulomb drag signal emerges between the N = 0 and N = 1 Landau levels. These findings suggest the important role of the orbital index and vertical displacement field in interlayer Coulomb interaction within the quantum Hall regime of coupled bilayer systems.
, , # Orbital dependent Coulomb drag in electron-hole bilayer graphene heterostructures

Dataset DOI: [10.5061/dryad.612jm64km](https://doi.org/10.5061/dryad.612jm64km)

This Dryad package contains the source data (plain-text *.txt*) used to generate the main-text and Supplemental Material figures in the associated Physical Review Letters article “Orbital-Dependent Coulomb Drag in Electron-Hole Bilayer Graphene Heterostructures.”

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## 1. Experiment and measurement overview

**Device:** an electron–hole (e–h) double-layer system formed by two bilayer graphene sheets separated by an insulating hBN barrier (~3.5 nm). Carrier densities in each bilayer are tuned by top gate voltage (*V~t~*) and bottom gate voltage (*V~b~*). An interlayer bias (*V~interlayer~*) is applied between the two bilayer graphene sheets.

**Coulomb drag measurement:** an AC current *I~drive~* = 1 nA at 17 Hz is driven through the drive layer (top bilayer graphene). Voltages are measured in the drag layer (bottom bilay...,