Tip-enhanced strong coupling of single emitters at room temperature for quantum coherent control

Quantum applications of single emitters are limited by dephasing and have relied on microcavities at low temperature to overcome decoherence. In contrast, plasmonic nanocavities achieve strong light-matter coupling at room temperature due to their deep sub-diffraction mode volumes, clearing a path towards coherent control of quantum emitters under ambient conditions. Here, using plasmonic Au nano-tips manipulated with atomic force microscopy based, sub-nm precision, above a Au substrate, a tunable nano-cavity is formed. In tip-enhanced strong coupling (TESC) of single quantum emitters at room temperature we demonstrate coupling strengths greater than 180 meV with single CdSe/ZnS quantum dots from photoluminescence emission. Additionally, we characterize hybridized energy states across multiple quantum dot measurements, with photon statistics and lifetimes determined from time correlated single photon measurements.