Anomalous low-temperature Coulomb drag in graphene-GaAs heterostructures.
Springer Science and Business Media LLC
MetadataShow full item record
Gamucci, A., Spirito, D., Carrega, M., Karmakar, B., Lombardo, A., Bruna, M., Pfeiffer, L., et al. (2014). Anomalous low-temperature Coulomb drag in graphene-GaAs heterostructures.. Nat Commun, 5 5824. https://doi.org/10.1038/ncomms6824
Vertical heterostructures combining different layered materials offer novel opportunities for applications and fundamental studies. Here we report a new class of heterostructures comprising a single-layer (or bilayer) graphene in close proximity to a quantum well created in GaAs and supporting a high-mobility two-dimensional electron gas. In our devices, graphene is naturally hole-doped, thereby allowing for the investigation of electron-hole interactions. We focus on the Coulomb drag transport measurements, which are sensitive to many-body effects, and find that the Coulomb drag resistivity significantly increases for temperatures <5-10 K. The low-temperature data follow a logarithmic law, therefore displaying a notable departure from the ordinary quadratic temperature dependence expected in a weakly correlated Fermi-liquid. This anomalous behaviour is consistent with the onset of strong interlayer correlations. Our heterostructures represent a new platform for the creation of coherent circuits and topologically protected quantum bits.
Engineering and Physical Sciences Research Council (EP/K01711X/1)
Engineering and Physical Sciences Research Council (EP/K017144/1)
European Commission (604391)
Engineering and Physical Sciences Research Council (EP/L016087/1)
European Commission (289968)
External DOI: https://doi.org/10.1038/ncomms6824
This record's URL: https://www.repository.cam.ac.uk/handle/1810/280019