Topological charge pumping by a sliding moiré pattern
Manato Fujimoto, Henri Koschke, Mikito Koshino
Abstract
We study the adiabatic topological charge pumping driven by interlayer sliding in the moir\'e superlattices. We show that, when we slide a single layer of the twisted bilayer system relatively to the other, a moir\'e pattern flow and a quantized transport of electrons occur. The number of pumped charges is quantized to a sliding Chern number, which is related to the interlayer sliding degree of freedom. In the twisted bilayer graphene, the topological pumping current flows perpendicularly to the sliding direction when the Fermi energy is in the energy gap above or below the nearly-flat bands.
Topics & Concepts
SuperlatticeCondensed matter physicsPhysicsFermi energyElectronTopology (electrical circuits)Adiabatic processBilayer grapheneCharge (physics)Topological quantum numberFermi levelGrapheneQuantum mechanicsMathematicsCombinatoricsTopological Materials and PhenomenaQuantum and electron transport phenomenaQuantum many-body systems