Non-Markovianity induced by a single-photon packet in a one-dimensional waveguide

TL;DR

This paper demonstrates how a single-photon packet in a one-dimensional waveguide can induce and measure non-Markovian quantum dynamics without the need for mirrors, highlighting the role of initial field states and controllable parameters.

Contribution

It introduces a method to generate and detect non-Markovianity in a waveguide system using a single-photon packet, bypassing traditional cavity setups.

Findings

Non-Markovianity depends on photon linewidth and central frequency.

A $b1$-phase shift indicates non-Markovian behavior.

Distinct signatures of NM are observable in waveguide output channels.

Abstract

The concept of non-Markovianity (NM) in quantum dynamics is still an open debate. Understanding how to generate and measure NM in specific models may aid in this quest. In quantum optics, an engineered electromagnetic environment coupled to a single atom can induce NM. The most common scenario of structured electromagnetic environment is an optical cavity, composed by a pair of mirrors. Here, we show how to generate and measure NM on a two-level system coupled to a one-dimensional waveguide with no mirrors required. The origin of the non-Markovian behavior lies in the initial state of the field, prepared as a single-photon packet. We analyze how NM depends on two experimentally controllable parameters, namely, the linewidth of the packet and its central frequency. We relate the presence of NM to a $\pi$-phase shift between incoming and emitted fields. We also show how the two output channels of the waveguide provide distinct signatures of NM, both experimentally accessible.