Confinement of long-lived interlayer excitons in WS$_2$/WSe$_2$ heterostructures

Abstract

Interlayer excitons in layered materials constitute a novel platform to study many-body phenomena arising from long-range interactions between quantum particles. The ability to localise individual interlayer excitons in potential energy traps is a key step towards simulating Hubbard physics in artificial lattices. Here, we demonstrate spatial localisation of long-lived interlayer excitons in a strongly confining trap array using a WS 2 /WSe 2 heterostructure on a nano-patterned substrate. We detect long-lived interlayer excitons with lifetime approaching 0.2 ms and show that their confinement results in a reduced lifetime in the microsecond range and stronger emission rate with sustained optical selection rules. The combination of a permanent dipole moment, spatial confinement and long lifetime places interlayer excitons in a regime that satisfies one of the requirements for observing long-range dynamics in an optically resolvable trap lattice.

Quantum Nanophotonics in Two-Dimensional Materials

“…Figure 3g). Another promising route 139 to generate quantum emitters in 2D materials is based on the moirésuperpotential to trap interlayer excitons 140,141 in MoSe 2 /WSe 2 heterostructures. 142−145 Initial results reveal very narrow lines (<meV), show distinct magnetic field dependence, 143,146 and antibunching photon statistics were observed, 147 thus, proving the existence of single-photon generation.…”