Deterministic coupling of site-controlled quantum emitters in monolayer WSe2 to plasmonic nanocavities

Abstract

Solid-state single-quantum emitters are a crucial resource for on-chip photonic quantum technologies and require efficient cavity-emitter coupling to realize quantum networks beyond the single-node level 1,2 . Previous approaches to enhance light-matter interactions rely on forming nanocavities around randomly located quantum dots 3-8 or color centers 9,10 but lack spatial control of the quantum emitter itself that is required for scaling. Here we demonstrate a deterministic approach to achieve Purcell-enhancement at lithographically defined locations using the sharp corner of a metal nanocube for both electric field enhancement and to deform a two-dimensional material. For a 3×4 array of strain-induced exciton quantum emitters formed into monolayer WSe2 we show spontaneous emission rate enhancement with Purcell-factors (FP) up to FP=1050 (average FP=272), single-photon purification, and cavity-enhanced quantum yields increasing from initially 1% to 15%. The utility of our nanoplasmonic platform is applicable to other 2D material, including boron nitride, opening new inroads in quantum photonics.

Enhanced Optical Emission from 2D InSe Bent onto Si‐Pillars

“…The spatial modulation of the PL emission from InSe over the Si‐pillars is qualitatively different from that reported for single and bi‐layer TMDCs. [ 33–41 ] In TMDCs sharp emission lines are observed at low‐temperature and assigned to the recombination of excitons from localized states. These arise from crystal defects, non‐homogeneous strain and/or nano wrinkles intentionally created by exfoliating and/or transferring the TMDCs onto nanopillars, rough metallic surfaces coated with dielectrics, and/or created by intentionally structural damage of the layers.…”

Coupling of deterministically activated quantum emitters in hexagonal boron nitride to plasmonic surface lattice resonances

“…Recent studies have shown that hBN grown via chemical vapor deposition (CVD) can contain a high density of point defects that can be "activated" (i.e., transformed into a fluorescent state) either by thermal annealing or substrate-engineering [33,34]. In this latter case, the emitter position (and, to some extent, the areal concentration [35]) can be controlled, hence providing opportunities for integration with photonic structures [36,37].…”

Deterministic coupling of quantum emitters in WSe2 monolayers to plasmonic nanocavities

“…34,35 However, the deterministic coupling of well-ordered quantum emitters in atomically thin materials with resonant plasmonic modes has only now been achieved. 33,36…”