Nano‐Cavity QED with Tunable Nano‐Tip Interaction

Abstract

Quantum state control of two-level emitters is fundamental for many information processing, metrology, and sensing applications. However, quantum-coherent photonic control of solid-state emitters has traditionally been limited to cryogenic environments, which are not compatible with implementation in scalable, broadly distributed technologies. In contrast, plasmonic nano-cavities with deep sub-wavelength mode volumes have recently emerged as a path toward room temperature quantum control. However, optimization, control, and modeling of the cavity mode volume are still in their infancy. Here recent demonstrations of plasmonic tip-enhanced strong coupling (TESC) with a configurable nano-tip cavity are extended to perform a systematic experimental investigation of the cavity-emitter interaction strength and its dependence on tip position, augmented by modeling based on both classical electrodynamics and a quasinormal mode framework. Based on this work, a perspective for nano-cavity optics is provided as a promising tool for room temperature control of quantum coherent interactions that could spark new innovations in fields from quantum information and quantum sensing to quantum chemistry and molecular opto-mechanics.