Measurement of deep-subwavelength emitter separation in a waveguide-QED system

TL;DR

This paper introduces a novel method for measuring extremely small emitter separations in waveguide-QED systems, enabling detection of tiny local variations and counting emitters within diffraction-limited spots.

Contribution

The authors develop a new measurement technique for deep-subwavelength emitter separation and emitter number determination in waveguide-QED systems, with potential sensing applications.

Findings

Able to measure deep-subwavelength emitter separations

Can determine the number of emitters within a diffraction-limited spot

Detects ultrasmall changes in emitter separation for sensing applications

Abstract

In the waveguide quantum electrodynamics (QED) system, emitter separation plays an important role for its functionality. Here, we present a method to measure the deep-subwavelength emitter separation in a waveguide-QED system. In this method, we can also determine the number of emitters within one diffraction-limited spot. In addition, we also show that ultrasmall emitter separation change can be detected in this system which may then be used as a waveguide-QED-based sensor to measure tiny local temperature/strain variation.