科研之友
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摘要
Dirac fermions have been actively investigated in recent years, both theoretically and experimentally. Some materials hosting Dirac fermions are natural platforms for interlayer coherence effects such as Coulomb drag and exciton condensation. Here we determine the role played by the anomalous Hall effect in Coulomb drag in doped massive Dirac fermion systems. We focus on topological insulator films with out-of plane magnetizations in both the active and passive layers. The transverse response of the active layer is dominated by a topological term arising from the Berry curvature. We show that the topological mechanism does not contribute to Coulomb drag, yet the longitudinal drag force in the passive layer gives rise to a transverse drag current. This anomalous Hall drag current is independent of the active-layer magnetization, a fact that can be verified experimentally. It depends nonmonotonically on the passive-layer magnetization, exhibiting a peak that becomes more pronounced at low densities. These findings are expected to stimulate new experiments and quantitative studies of anomalous Hall drag.
- 出版日期2017-5-30
