Optical simulation of atomic decay enhancement and suppression

TL;DR

This paper presents an optical simulation of atomic decay processes into engineered reservoirs using coupled waveguides, providing analytic and numerical insights into decay enhancement and suppression phenomena.

Contribution

It introduces a novel optical simulation method for atomic decay into engineered reservoirs, combining analytic approximations with numerical simulations to analyze non-Markovian decay behaviors.

Findings

Analytic formulas for decay amplitudes at small distances

Effective decay rate estimation for long distances

Demonstration of decay enhancement and suppression using specific coupling profiles

Abstract

We discuss the decay of a two-level system into an engineered reservoir of coupled harmonic oscillators in the single-excitation manifold and propose its optical simulation with an homogeneous chain of coupled waveguides where individual elements couple to an external waveguide. We use two approaches to study the decay of the optical analogue for the probability amplitude of the two-level system being in the excited state. A Born approximation allows us to provide analytic closed-form amplitudes valid for small propagation distances. A Fourier-Laplace approach allows us to estimate an effective decay rate valid for long propagation distances. In general, our two analytic approximations match our numerical simulations using coupled mode theory and show non-Markovian decay into the engineered reservoir. In particular, we focus on two examples that provide enhancement or suppression of the decay decay rate using flat-top or Gaussian coupling distributions.