Anomalous Coulomb drag between bilayer graphene and a GaAs electron gas. (31st October 2017)

• Record Type: Journal Article
• Authors: Simonet, Pauline; Hennel, Szymon; Overweg, Hiske; Steinacher, Richard; Eich, Marius; Pisoni, Riccardo; Lee, Yongjin; Märki, Peter; Ihn, Thomas; Ensslin, Klaus; Beck, Mattias; Faist, Jérôme
• Is Part Of: New journal of physics. Volume 19:Number 10(2017:Oct.)
• Publication Date: 2017-10-31
• Subjects: Coulomb drag -- graphene -- GaAs -- electron gas; Physics -- Periodicals; Physics; Periodicals; 530.05
• DOI: 10.1088/1367-2630/aa887e
• Languages: English
• ISSNs: 1367-2630

Abstract

Abstract: We report on Coulomb drag experiments between a bilayer graphene flake and a GaAs two-dimensional electron gas, where the charge-carrier densities of both systems can be tuned independently. For both p- and n-type graphene charge carriers, we observe that the Coulomb drag unexpectedly changes direction when the temperature is lowered. We find this phenomenon to be dominant when the Fermi wave vector in graphene is larger than in GaAs. At temperatures above ≈ 70 K, the drag signal is consistent with momentum exchange. In all discussed regimes, the Onsager relation is respected.