Coulomb Drag Mechanisms in Graphene

Recent measurements revealed an anomalous Coulomb drag in graphene, hinting at new physics at charge neutrality. The anomalous drag is explained by a new mechanism based on energy transport, which involves interlayer energy transfer, coupled to charge flow via lateral heat currents and thermopower....

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Bibliographic Details
Main Authors: Abanin, Dmitry A., Song, Justin C. W., Levitov, Leonid
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:en_US
Published: American Chemical Society (ACS) 2015
Online Access:http://hdl.handle.net/1721.1/98224
https://orcid.org/0000-0002-4268-731X
Description
Summary:Recent measurements revealed an anomalous Coulomb drag in graphene, hinting at new physics at charge neutrality. The anomalous drag is explained by a new mechanism based on energy transport, which involves interlayer energy transfer, coupled to charge flow via lateral heat currents and thermopower. The old and new drag mechanisms are governed by distinct physical effects, resulting in starkly different behavior, in particular for drag magnitude and sign near charge neutrality. The new mechanism explains the giant enhancement of drag near charge neutrality, as well as its sign and anomalous sensitivity to the magnetic field. Under realistic conditions, energy transport dominates in a wide temperature range, giving rise to a universal value of drag which is essentially independent of the electron–electron interaction strength.