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

Alejandro R. -P. Montblanch, Dhiren M. Kara, Ioannis Paradisanos, Carola M. Purser, Matthew S. G. Feuer, Evgeny M. Alexeev, Lucio Stefan, Ying Qin, Mark Blei, Gang Wang, Alisson R. Cadore, Pawel Latawiec, Marko Lončar, Sefaattin Tongay, Andrea C. Ferrari, Mete Atatüre

Published 2020-05-05Version 1

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 nanopatterned 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.