Current-Induced Reversal of Anomalous Hall Conductance in Twisted Bilayer Graphene
Ying Su, Shi‐Zeng Lin
Abstract
It is observed experimentally that the sign of the Hall resistance can be flipped by a dc electric current in the twisted bilayer graphene (TBG) at 3/4 filling of the fourfold degenerate conduction flat bands. The experiment implies a switching of the valley polarization (VP) and topology in TBG. Here we present a theory on the current-induced switching of VP and topology. The presence of current in the bulk causes the redistribution of electron occupation in bands near the Fermi energy, which then deforms and shifts the band dispersion due to the Coulomb interaction. Above a critical current, the original occupied and empty bands can be swapped, resulting in the switching of VP and topology.
Topics & Concepts
Bilayer grapheneCondensed matter physicsConductanceGrapheneHall conductivityMaterials scienceBilayerCurrent (fluid)Hall effectPhysicsElectrical resistivity and conductivityNanotechnologyQuantum mechanicsMembraneThermodynamicsGeneticsBiologyGraphene research and applicationsQuantum and electron transport phenomenaTopological Materials and Phenomena