Waveguide quantum electrodynamics in squeezed vacuum

TL;DR

This paper develops a theoretical framework for multi-emitter waveguide QED systems in squeezed vacuum, revealing position-dependent effects on interactions, dephasing, and entanglement, with potential for controllable quantum state engineering.

Contribution

It introduces a master equation including emitter positions relative to squeezing sources, extending previous models and enabling control over quantum dynamics in waveguide QED.

Findings

Dipole-dipole interactions depend on emitter separation

Two-photon processes depend on emitter positions relative to sources

Maximal entangled NOON states can be achieved under specific conditions

Abstract

We study the dynamics of a general multi-emitter system coupled to the squeezed vacuum reservoir and derive a master equation for this system based on the Weisskopf-Wigner approximation. In this theory, we include the effect of positions of the squeezing sources which is usually neglected in the previous studies. We apply this theory to a quasi-one-dimensional waveguide case where the squeezing in one dimension is experimentally achievable. We show that while dipole-dipole interaction induced by ordinary vacuum depends on the emitter separation, the two-photon process due to the squeezed vacuum depends on the positions of the emitters with respect to the squeezing sources. The dephasing rate, decay rate and the resonance fluorescence of the waveguide-QED in the squeezed vacuum are controllable by changing the positions of emitters. Furthermore, we demonstrate that the stationary maximum entangled NOON state for identical emitters can be reached with arbitrary initial state when the center-of-mass position of the emitters satisfies certain condition.