Layer-dependent correlated phases in WSe2/MoS2 moire superlattice

Electron correlation plays an essential role in the macroscopic quantum phenomena in the moire heterostructure, such as antiferromagnetism and correlated insulating phases. Unlike the phenomena where the interaction involves only electrons in one layer, the interaction of distinct phases in two or more layers represents a new horizon forward, such as the one in the Kondo lattice model. Here, using interlayer excitons as a probe, we show that the interlayer interactions in heterobilayers of tungsten diselenide and molybdenum disulfide (WSe2/MoS2) can be electrically switched on and off, resulting in a layer-dependent correlated phase diagram, including single-layer, layer-selective, excitonic-insulator and layer-hybridized regions. We demonstrate that these correlated phases affect the interlayer exciton non-radiative decay pathways. These results reveal the role of strong correlation on interlayer exciton dynamics and pave the way for studying the layer-resolved strong correlation behaviour in moire heterostructures. The authors demonstrate electrical on/off switching of interlayer interactions in tungsten diselenide/molybdenum disulfide heterobilayers, the phase diagram of which contains layer-dependent correlated regions that reveal the role of strong correlations in interlayer exciton dynamics.

Automated summary

Using interlayer excitons as a probe, the authors demonstrate that interlayer interactions can be electrically switched on and off in heterobilayers of tungsten diselenide and molybdenum disulfide (WSe2/MoS2), resulting in a layer-dependent correlated phase diagram. They show that these correlated phases affect the decay pathways of interlayer excitons, revealing the role of strong correlation in their dynamics. This study paves the way for studying layer-resolved strong correlation behavior in moire heterostructures.