Non-Markovianity of photon dynamics in a birefringent crystal

TL;DR

This paper investigates the non-Markovian behavior of photon polarization in birefringent crystals using a quantum process measure, revealing that many processes previously considered Markovian are actually non-Markovian, with implications for quantum system control.

Contribution

The study introduces a method to classify non-Markovianity in photon dynamics that appear Markovian under existing criteria, enhancing understanding and experimental characterization.

Findings

All processes previously identified as Markovian are non-Markovian.

The method enables classification of non-Markovianity in Markovian-appearing processes.

Experimental feasibility demonstrated for optical characterization of photon dynamics.

Abstract

The way a principle system and its environment interact characterizes the non-Markovianity of the dynamics. Herein, we investigate the non-Markovian dynamics of photon polarization in a birefringent crystal. We consider the so-called `quantity of quantum-mechanical process' first defined by Hsieh et al. [Sci. Rep. 7, 13588 (2017)]. The non-Markovianity of the photon dynamics is evaluated by examining the quantity of quantum-mechanical process varying with time, and the difference between the quantity of quantum-mechanical process in a complete dynamics and that in a process composed of two subprocesses. We show that all of the processes identified as Markovian in the seminal study of Liu et al. [Nat. Phys. 7, 931 (2011)] can actually be identified as non-Markovian. The presented method enables us to classify non-Markovianity in the dynamical processes that are classified as Markovian by existing verification criteria. Overall, the results confirm the feasibility of performing the experimental characterization of photon dynamics using an all-optical setup and provide a useful insight into enhancing the accuracy and control of quantum system designs for quantum engineering applications.