Entanglement assisted probe of the non-Markovian to Markovian transition in open quantum system dynamics

TL;DR

This paper experimentally investigates the transition from non-Markovian to Markovian dynamics in an open quantum system using a superconducting qubit setup, demonstrating control over environmental memory effects and entanglement stability.

Contribution

It introduces an experimental method to engineer and observe the non-Markovian to Markovian transition in a superconducting qubit system, including the creation of decoherence-free subspaces.

Findings

Observation of entanglement collapse and revival indicating quantum memory effects

Controlled transition from non-Markovian to Markovian dynamics by thermal photon population

Stabilization of entanglement via quantum Zeno effect in a decoherence-free subspace

Abstract

We utilize a superconducting qubit processor to experimentally probe non-Markovian dynamics of an entangled qubit pair. We prepare an entangled state between two qubits and monitor the evolution of entanglement over time as one of the qubits interacts with a small quantum environment consisting of an auxiliary transmon qubit coupled to its readout cavity. We observe the collapse and revival of the entanglement as a signature of quantum memory effects in the environment. We then engineer the non-Markovianity of the environment by populating its readout cavity with thermal photons to show a transition from non-Markovian to Markovian dynamics, ultimately reaching a regime where the quantum Zeno effect creates a decoherence-free subspace that effectively stabilizes the entanglement between the qubits.